Prodegradation in nonwovens

ABSTRACT

A biologically degradable multi-component polymer fiber, in particular bi-component fibers, with advantageous physical properties, to a process for its production, as well as to its use.

PRIORITY

The present application claims priority from U.S. Provisional PatentApplication No. 63/323,790, filed on Mar. 25, 2022, the entire contentsof which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a biologically degradable polymer fiber withadvantageous physical properties, to a process for its production, aswell as to its use.

BACKGROUND OF THE INVENTION

Polymer fibers, i.e., fibers based on synthetic polymers, are producedindustrially on a huge scale. In this regard, the basic syntheticpolymer is processed using a melt spinning process. To this end, thethermoplastic polymeric material is melted and fed in the liquid stateinto a spinning beam by means of an extruder. From this spinning beam,the molten material is fed to what are known as spinnerets. Thespinneret usually comprises a spinneret plate provided with a pluralityof holes out of which the individual capillaries (filaments) of thefiber are extruded. In addition to the melt spinning process, wetspinning or solvent spinning processes are also used for the productionof spun fibers. Here, instead of a melt, a highly viscous solution of asynthetic polymer is extruded through dies with fine holes. When largenumbers of individual spinnerets are charged at the same time and inparallel by the same flow of polymer melt, the person skilled in the artterms this a multiple spinning process.

The polymer fibers produced in this manner are used for textile and/ortechnical applications. In these applications, it is of advantage forthe polymer fibers to have high mechanical strength so that thepost-processing of the fibers can be carried out without problems, forexample by drawing on rolling mills. It is also advantageous for thepolymer fibers, in particular when in the form of nonwovens, to have lowthermal shrinkage.

Modifying or equipping polymer fibers for the respective end use or forthe necessary intermediate treatment steps, for example drawing and/orcrimping, is usually carried out by applying suitable softening agentsor dressings which are applied to the surface of the prepared polymerfibers or the polymer fibers to be treated.

A further possibility for modification is the chemical modification ofthe polymer skeleton itself, for example by incorporatingflame-retardant co-monomers into the polymeric main and/or side chain.

Furthermore, additives, for example antistatic agents or coloredpigments, can be introduced into the molten thermoplastic polymer or canbe introduced into the polymer fiber during the multiple spinningprocess.

Recently, there has been a surge in the development of fiber systemswhich on the one hand satisfy the requirements set out above, andfurthermore which exhibit good biological degradability, and on theother hand require few or no changes, so that existing processes andequipment can still be used.

Recently, there has been an additional surge in the development of fibersystems which on the one hand satisfy the requirements set out above,and furthermore which preferably can be produced at least in part fromsustainable raw materials, and on the other hand require few or nochanges, so that existing processes and equipment can still be used.

In biologically degradable fibers, because of the chronological sequenceof the degradation processes, which are influenced by various factors,there is often a poor and poorly controllable relationship betweenmaximum service life of the product and the time period over which theanticipated biological degradation takes place.

Thus, there is a need for the provision of a polymer fiber thebiological degradability of which can be tailored to the intended enduse and also which is compatible with existing post-processing offibers.

BRIEF SUMMARY OF THE INVENTION

The present invention allows the degradation behavior of the fiber to becontrolled by using two components which behave differently with respectto each other as regards degradation.

The need is satisfied by means of the multi-component polymer fiber inaccordance with the invention, wherein the polymer fiber: comprises atleast one component A and at least one component B, the component Acomprises a thermoplastic polymer A, the component B comprises athermoplastic polymer B, characterized in that the component Aadditionally has at least one additive A which increases the biologicaldegradability of the multi-component fiber and the component B does nothave an additive B which increases the biological degradability of themulti-component fiber, or the component B additionally has at least oneadditive B which increases the biological degradability of themulti-component fiber and the component A does not have an additive Awhich increases the biological degradability of the multi-componentfiber, or the component A additionally has at least one additive A andthe component B additionally has at least one additive B which togetherincrease the biological degradability of the multi-component fiber, withthe proviso that when (i) the thermoplastic polymer A and thethermoplastic polymer B are identical, the additives A and B aredifferent, or (ii) when the additives A and B are identical,thermoplastic polymer A and thermoplastic polymer B are different.

According to another broad form of the present invention, the firstresin has a first degradation additive and a first defined performance.The second resin has a second degradation additive with a second definedperformance. The first performance is different than second performance.Performances may be functional, aesthetic, or the combinations thereof.

Producers that utilize nonwoven components in their products, often seekto attain greater performance from fewer overall components so as tominimize production steps, reduce potential quality issues, and thecosts associated therewith. To attain greater overall performance at acomponent level, combining sometimes disparate functionalities intolaminate or composite nonwoven structure is required. Functionalities ofinterest are defined by the intended application of the final product.Exemplar functionalities for products targeting hygienic applicationsmay include elastomeric recovery, liquid barrier, fluid management,solids retention, antimicrobial, anti-odor, color masking,breathability, and combinations thereof. When creating suchmultifunction nonwoven materials, the chemical composition(s) and thebest means for inducing predictable degradation of such chemicalcompositions, may necessitate use of differing levels of a givenprodegradant additive(s) and/or use of one or more prodegradantadditives to achieve the desired overall nonwoven component degradationbehavior.

A particular embodiment of interest is the utilization of multibeamspunlaid nonwoven technology wherein one or more beams of such a linewill comprise a first base resin, having a first defined performancewherein a first prodegradant additive is used. Further, the samemultibeam line may sequentially laydown a second resin, comprising asecond prodegradant additive, which exhibits a second definedperformance. As an example, the first resin may utilize a colorant toenhance masking behavior of a hygiene product and include a firstprodegradant additive. This first combination may be laid down by one ormore spunbond beams. In this same example, a second resin may utilize anelastomer to provide enhanced conformability, requiring a secondprodegradant, and is laid down on the first combination by one or moresubsequent spunbond beams.

It is within the purview of this instant invention that one or moremeltblown layers may be added between any two spunbond layers.

It is within the purview of this instant invention that one or morespunbond streams, comprising said first and second compositions, may becombined prior to lay down to achieve an intimately intermingledcomposite of the compositions.

It is within the purview of this instant invention that functionalitiesmay be obtained through the combination of two or more supplementaladditives, wherein the supplemental additives provide the base resinwith additional performance and/or aesthetic attributes.

It is within the purview of this instant invention of multibeam nonwovenfabric with differing composition of bio-degradants.

Gradient of layers with increasing/decreasing biodegradation behavior ineach layer (SS to SMS to SSMMMS)

Triggering sequential degradation of a nonwoven so as to have different“phases” in the products degradation profile (envisioning Agriculturalapplications in particular, with other opportunities to be identified)

To achieve laminate or composite nonwoven materials with a desireddegradation behavior, it may be of interest to specify a degradationprofile defined by a sequential degradation of the overall material. Thesequential degradation behavior may include a nonwoven material wherethe first composition degrades at a first rate that is different thanthe second composition. Such a degradation profile may create a clockmechanism wherein the second composition is not triggered to degradeuntil said first composition has achieved a defined level ofdegradation. For example, the first composition may include a UVwavelength blocking additive and thermal sensitive prodegradantadditive, wherein the UV wavelength is used as a trigger in the secondcomposition. As the composite or laminate nonwoven is exposed toenvironmental conditions including thermal triggering conditions and UVlight, the first composition begins to degrade while the secondcomposition remains in a quiescent state. Once the first composition hassufficient degraded due to the thermal condition, the second compositionis then allowed to react in increasing degrees with the UV lighttrigger, thus inducing the second, and final, degradation of thenonwoven material.

In one form of the invention, the nonwoven material has a higher dosingof the prodegradant additive on a coarse fiber layer in contact with afiner fiber layer such that the coarser fiber layer triggers thedegradation of the finer fiber layer.

In another form of the invention, the nonwoven material includes anelastomer with direct or phased degradation profile.

According to yet another form of the present invention, the nonwovenmaterial includes stabilizing behavior of TiO2 biodegradation systems,including the type of TiO2 used.

We have also seen potential synergistic activities of certain softadditives (fatty acid amides specifically) and antioxidant stabilitypackages. Regarding the antioxidant package, we are exploring the veryinteresting aspect of creating “chemical clocks” that extend the in-uselife, despite being presented a trigger condition, before entering intothe degradation cascade (critical for Ag). A “consumable” antioxidantthat decreases in concentration during environmental exposure. Potentialfatty acid amide impact on prodegradant additive behavior. A higherdosing prodegradant additive in the coarse fiber layer immediately incontact with a finer fiber layer which contains antioxidant stabilitypackage. The triggering of the finer fiber layer is adjusted orcontrolled by both the coarser fiber composition and antioxidantcomposition.

Use of probiotic treatment to ensure specific degradation results areachieved, which is not limited to nonwoven materials in the broadestform of the present invention.

Complete degradation of materials containing one or more prodegradantchemistries often relies on the action of bio-organisms to reduce thebase resin structure to its simplest form(s). Ensuring that completedegradation occurs in a known and predictable way is complicated byhaving adequate exposure to suitable bio-organisms at the proper time inthe degradation profile. It is envisioned that suitable probiotics toachieve complete degradation be used in the form of environmentally andhealth-safety innocuous bacteria that are “preloaded” into and/or upon aprodegradant treated material. Once the material has achieved suitablereduction of the resin structure, the preloaded bacteria are then ableto complete the degradation pathway irrespective of suitablebio-organisms being present in the normal environment. Such probioticsmay blend unobtrusively into the environment, or terminate due to theloss of sustaining nutrients, inherent intolerance to increasingconcentrations or metabolic by-products, or the presence of triggeredchemical reactions that inhibit further proliferation.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings forming part of the specification, in whichlike numerals are employed to designate like parts throughout the same,

FIGS. 1 a and 1 b show the biodegradation of the fibre made according tothe present invention versus the control;

FIG. 2 a is a microphotograph of a control nonwoven fabric versus anonwoven made according to the present invention;

FIG. 2 b is a microphotograph of the individual fibers of the controlnonwoven fabric of FIG. 2 a and the nonwoven made according to thepresent invention of FIG. 2 a;

FIG. 2 c is a microphotograph of a control nonwoven fabric that has beenmechanically stressed versus a nonwoven made according to the presentinvention that has been mechanically stressed;

FIG. 2 d is a microphotograph of the individual fibers of the controlnonwoven fabric that was mechanically stressed of FIG. 2 c and theindividual fibers of the mechanically stressed nonwoven made accordingto the present invention of FIG. 2 c ; and

FIG. 2 e is a microphotograph of the fractured portions of individualfibers of the control nonwoven fabric that was mechanically stressed ofFIG. 2 d and the individual fibers of the mechanically stressed nonwovenmade according to the present invention of FIG. 2 d.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the context of the present invention, an increased biologicaldegradability of the multi-component fibre means that thismulti-component fibre, compared with a multi-component fibre withoutadditives A and/or B, is degraded more rapidly, wherein thedetermination is carried out in accordance with at least one methodselected from the group (i) ASTM D5338-15 (2021) (Standard Test Methodfor Determining Aerobic Biodegradation of Plastic Materials UnderControlled Composting Conditions, Incorporating ThermophilicTemperatures (DOI: 10.1520/D5338-15R21) ASTM International, WestConshohocken, P A, 2015, www.astm.org), (ii) ASTM D6400-12 (StandardSpecification for Labeling of Plastics Designed to be AerobicallyComposted in Municipal or Industrial Facilities) (DOI:10.1520/D6400-12), (iii) ASTM D5511 (ASTM D5511-11 Standard Test Methodfor Determining Anaerobic Biodegradation of Plastic Materials UnderHigh-Solids Anaerobic Digestion Conditions (DOI: 10.1520/D5511-11) andASTM D5511-18 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-SolidsAnaerobic-Digestion Conditions; (DOI: 10.1520/D5511-18)), (iv) ASTMD6691 (ASTM D6691-09 Standard Test Method for Determining AerobicBiodegradation of Plastic Materials in the Marine Environment by aDefined Microbial Consortium or Natural Sea Water Inoculum) (DOI:10.1520/D6691-09) and ASTM D6691-17, Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in the MarineEnvironment by a Defined Microbial Consortium or Natural Sea WaterInoculum (DOI: 10.1520/D6691-17)), (v) ASTM D5210-92 (AnaerobicDegradation in the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92),(vi) PAS 9017:2020 (Plastics—Biodegradation of polyolefins in anopen-air terrestrial environment —Specification), ISBN 978 0 539 174786; 2021-10-31, (vii) ASTM D5988 (ASTM D5988-12 Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in Soil) (DOI:10.1520/D5988-12), ASTM D5988-18 Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials in Soil (DOI:10.1520/D5988-18), ASTM D5988-03 Standard Test Method for DeterminingAerobic Biodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), (viii) EN13432:2000-12 Packaging—Requirements for packaging recoverable throughcomposting and biodegradation—Test scheme and evaluation criteria forthe final acceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS 83.080.01) Determination of the ultimateaerobic biodegradability of plastic materials under controlledcomposting conditions (Method by analysis of evolved carbon dioxide),(x) EN 14995:2007-03—Plastics—Evaluation of compostability (DOI:10.31030/9730527) or (xi) ISO 17088:2021-04 (Specifications forcompostable plastics) (ICS 83.080.01).

When processed using the (staple fibre) spinning process, themulti-component polymer fibre in accordance with the invention isusually deposited as a tow and subsequently drawn on a rolling millusing the usual methods and then post-treated. The tow can also beprocessed further directly and so deposition of the tow in what areknown as cans can be entirely or partially dispensed with.

When processed using the (filament) spinning process, themulti-component polymer fibre in accordance with the invention can becooled directly following exit from the spinneret and drawn anddeposited on a collecting belt or wound onto bobbins. The filaments maybe drawn further for further processing in order to increase theorientation of the molecular chains, in particular with a draw ratiobetween 0.5 and 3. Furthermore, it is possible to texturize thefilaments.

The combination of different biological degradabilities for thecomponents A and B means that the biological degradability of theproducts resulting from these multi-component polymer fibres can bedesigned and customized.

Textile fabrics, for example nonwovens, can be produced from themulti-component polymer fibres in accordance with the invention. Whenthe textile fabrics, in particular nonwovens, are consolidated usingthermobonding, it is advantageous for the melting point of thethermoplastic polymer in component A to be at least 5° C. higher thanthe melting point of the thermoplastic polymer in component B. In thisembodiment, the multi-component polymer fibres are preferablybi-component fibres in which component A forms the core and component Bforms the shell. Particularly preferably, the melting point of thethermoplastic polymer in component A is at least 10° C. higher than themelting point of the thermoplastic polymer in component B.

During thermobonding, the fibres are bonded together at the contact orcrossover points. When the component B formed from thermoplastic polymerB with additive B has a higher biological degradability than component Aformed from thermoplastic polymer A with additive A, the contact orcrossover points of the fibres are degraded together first and thetextile fabric, for example a nonwoven, disintegrates faster, whereuponthe overall degradability is increased.

Furthermore, it is possible to provide a multi-component fibre whichcomprises a very rapidly biologically degradable component A with atleast one further component B, wherein component B has a lowerbiological degradation rate than component A. In this manner, a stagedbiological degradation of the fibres can be obtained, giving rise totechnical advantages, for example a warning of mechanical failure, acomparatively high residual stability of the fibres with advancedbiological degradation, etc.

Further possible arrangements of the components in the multi-componentfibre in addition to the core/shell structure, wherein the core may beconcentric with and also may be eccentric with respect to the shell, area side-by-side structure, a matrix-fibril structure as well asslice-of-cake structures or orange-slice structures.

Furthermore, it is possible to provide multi-component polymer fibres,in particular bi-component polymer fibres, which combine a very rapidlybiologically degradable core (component A) produced from thermoplasticpolymer A and optionally an additive A, with an equally biologicallydegradable shell (component B) produced from thermoplastic polymer Bwith additive B, so that the component A is only biologically degradedwhen component B has already been biologically degraded. This isintended to accelerate the degradation, which sets in as soon ascomponent B has been degraded to a sufficient extent.

Thus, in a further aspect, the present invention provides a bi-componentfibre with a core/shell structure wherein, the component A forms thecore and the component B forms the shell of the fibre, the component Ain the core comprises thermoplastic polymer A, the component B comprisesa thermoplastic polymer B, the melting point of the thermoplasticpolymer in the component A in the core is at least 5° C. higher than themelting point of the thermoplastic polymer in the component B in theshell; preferably, the melting point is at least 10° C. higher,characterized in that the component A has a higher biologicaldegradability than the component B; preferably, the component A has atleast one additive A, or the component B has a higher biologicaldegradability than the component A; preferably, the component B has atleast one additive B.

The higher biological degradability is determined in accordance with atleast one method selected from the group formed by: ASTM D5338-15 (2021)Standard Test Method for Determining Aerobic Biodegradation of PlasticMaterials Under Controlled Composting Conditions, IncorporatingThermophilic Temperatures (DOI:10.1520/D5338-15R21) ASTM International,West Conshohocken, P A, 2015, www.astm.orq), ASTM D6400-12 (StandardSpecification for Labeling of Plastics Designed to be AerobicallyComposted in Municipal or Industrial Facilities) (DOI:10.1520/D6400-12), ASTM D5511 (ASTM D5511-11 Standard Test Method forDetermining Anaerobic Biodegradation of Plastic Materials UnderHigh-Solids Anaerobic-Digestion Conditions (DOI: 10.1520/D5511-11) andASTM D5511-18 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-SolidsAnaerobic-Digestion Conditions; (DOI: 10.1520/D5511-18)), ASTM D6691(ASTM D6691-09 Standard Test Method for Determining AerobicBiodegradation of Plastic Materials in the Marine Environment by aDefined Microbial Consortium or Natural Sea Water Inoculum) (DOI:10.1520/D6691-09) and ASTM D6691-17, Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in the MarineEnvironment by a Defined Microbial Consortium or Natural Sea WaterInoculum (DOI: 10.1520/D6691-17)), ASTM D5210-92 (Anaerobic Degradationin the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92), PAS 9017:2020(Plastics—Biodegradation of polyolefins in an open-air terrestrialenvironment—Specification), ISBN 978 0 539 17478 6; 2021-10-31, ASTMD5988 (ASTM D5988-12 Standard Test Method for Determining AerobicBiodegradation of Plastic Materials in Soil) (DOI: 10.1520/D5988-12),ASTM D5988-18 Standard Test Method for Determining AerobicBiodegradation of Plastic Materials in Soil (DOI: 10.1520/D5988-18),ASTM D5988-03 Standard Test Method for Determining AerobicBiodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), EN 13432:2000-12Packaging—Requirements for packaging recoverable through composting andbiodegradation—Test scheme and evaluation criteria for the finalacceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS 83.080.01) Determination of the ultimateaerobic biodegradability of plastic materials under controlledcomposting conditions (Method by analysis of evolved carbon dioxide), EN14995:2007-03—Plastics—Evaluation of compostability (DOI:10.31030/9730527) or ISO 17088:2021-04 (Specifications for compostableplastics) (ICS 83.080.01).

The bi-component fibre in accordance with the invention can therefore betailored for any intended purpose and any environment.

Because the component A has a higher biological degradability thancomponent B, firstly, the shell component B—which protects againstbiological degradability—is biologically degraded and after it hasdegraded, component A is degraded.

In this way, materials may be used as component A which have abiological degradability which is so high that they usually cannot beengineered, because their high biological degradability means that theyare is assumed to be unstable or unsuitable. The protective shell canalso have a retarding action, i.e. the shell initially at least slowsdown the biological degradability and after a specific time or period ofuse, a rapid biological degradation occurs.

Thus, for example, textile fabrics which have the one bi-component fibrein accordance with the invention, may be used in agriculture, in whichthe component A has a high biological degradability in accordance withASTM D5338-15 or ASTM D6400 or ASTM D5988, but is initially protected bythe shell. Textile fabrics of this type can be disposed of after theintended use by means of controlled composting.

A further advantage of the present invention is that textile fabricswhich have a bi-component fibre in accordance with the invention can beprovided which on the one hand, for example in agriculture, can be usedas intended, but which can reach the ocean via rivers in the event ofincorrect disposal. For this purpose, it is advantageous to use acomponent A which has a high biological degradability in accordance withASTM D6691. Because incorrect disposal usually breaks or damages theprotective shell, a controlled biological degradability, for example ina maritime environment, is ensured.

Because component B has a higher biological degradability than componentA, initially the shell component B is degraded, which leads to a fasterdisintegration of textile fabrics which have the bi-component fibres inaccordance with the invention. In this manner, for example, followingtheir intended use, hygiene articles can be composted in a controlledmanner in household waste or a sewage plant.

In this manner, a step-wise biological degradation may be obtained,bringing with it technical advantages, for example signaling mechanicalfailure, a comparatively high residual stability of the fibres in thecase of advanced biological degradation, etc.

The bi-component fibre in accordance with the invention may be afinite-length fibre, for example what is known as a staple fibre, or acontinuous fibre (filament). There are no critical restrictions to thelength of the aforementioned staple fibres, but in general they are 2 to200 mm, preferably 3 to 120 mm, particularly preferably 4 to 60 mm.

The individual linear density of the bi-component fibre in accordancewith the invention, preferably staple fibres, is preferably between 0.5and 30 dtex, in particular 0.7 to 13 dtex. For some applications, lineardensities of between 0.5 and 3 dtex and fibre lengths of <10 mm, inparticular <8 mm, particularly preferably <6 mm, particularly preferably<5 mm, are particularly suitable.

The cross-sectional proportion of the core with respect to the totalcross sectional area of the fibres is between 20% and 90% and thecross-sectional proportion of the shell with respect to the total crosssectional area of the fibres is between 80% and 10%.

The ratio of the cross sectional area of component A and component B mayalso contribute to fine tuning the biological degradability behavior ofthe fibre.

Particularly preferred-component polymer fibers are those in which theadditive A and/or additive B are selected from the group (i) basicalkali and/or alkaline earth compounds (pH>7 dissolved in water), inparticular carbonates, hydrogen carbonates, sulphates, particularlypreferably CaCO3, and alkaline additives, particularly preferably CaO,(ii) aliphatic polyesters, (iii) sugars, in particular mono-saccharides,di-saccharides and oligo-saccharides, (iv) catalysts fortransesterifications, in particular under basic conditions, (v)carbohydrates, in particular starch and/or cellulose, as well asmixtures thereof.

Particularly preferred-component polymer fibers are those in which thethermoplastic polymer A and/or the thermoplastic polymer B comprises atleast one polyester and the additive A and/or additive B is selectedfrom the group (i) basic alkali and/or alkaline earth compounds (pH>7dissolved in water), in particular carbonates, hydrogen carbonates,sulphates, particularly preferably CaCO3, and alkaline additives,particularly preferably CaO, (ii) aliphatic polyesters, (iii) sugars, inparticular mono-saccharides, di-saccharides and oligo-saccharides, (iv)catalysts for transesterifications, in particular under basicconditions, (v) carbohydrates, in particular starch and/or cellulose, aswell as mixtures thereof. The aforementioned aliphatic polyesters aredistinguished from the polyesters of the thermoplastic polymer A andpolymer B in respect of their chemical nature, i.e. the polyester of thethermoplastic polymer A and polymer B is an araliphatic polyester orcopolyester, which has been produced from polyols and aliphatic and/oraromatic dicarboxylic acids or their derivatives (anhydrides, esters) bymeans of polycondensation.

Particularly preferred additives A and/or additives B contain at leasttwo substances, wherein preferred combinations are: basic alkali and/oralkaline earth compounds (pH>7 dissolved in water), in particularcarbonates, hydrogen carbonates, sulphates, particularly preferablyCaCO3, and alkaline additives, particularly preferably CaO incombination with catalysts for transesterifications, in particular underbasic conditions; sugars, in particular mono-saccharides, di-saccharidesand oligo-saccharides, in combination with carbohydrates, in particularstarch and/or cellulose, as well as mixtures thereof; aliphaticpolyesters, optionally in combination with sugars, in particularmono-saccharides, di-saccharides and oligo-saccharides, orcarbohydrates, in particular starch and/or cellulose, as well asmixtures thereof.

Most preferred additives A for partially aromatic “araliphatic”polyester or copolyester as thermoplastic polymer A are containing atleast basic alkali and/or alkaline earth compounds (pH>7 dissolved inwater), in particular carbonates, hydrogen carbonates, sulphates,particularly preferably CaCO3, and alkaline additives, particularlypreferably CaO, preferably in combination with catalysts fortransesterifications, in particular under basic conditions; andaliphatic polyesters, especially aliphatic polyester having no sidechain carbon atoms, optionally in combination with (i) sugars, inparticular mono-saccharides, di-saccharides and oligo-saccharides, (ii)carbohydrates, in particular starch and/or (iii) cellulose, as well asmixtures thereof.

Out of the aforementioned particularly preferred-component polymerfibers are those preferred in which the thermoplastic polymer A ispolyester and the thermoplastic polymer B is a polyester being differentfrom the polyester in polymer A, and preferably is a co-polyester,and—each—the additive A and the additive B is independently selectedfrom the combination of basic alkali and/or alkaline earth compounds(pH>7 dissolved in water), in particular carbonates, hydrogencarbonates, sulphates, particularly preferably CaCO3, and alkalineadditives, particularly preferably CaO, preferably in combination withcatalysts for transesterifications, in particular under basicconditions; and aliphatic polyesters, especially aliphatic polyesterhaving no side chain carbon atoms, optionally in combination with (i)sugars, in particular mono-saccharides, di-saccharides andoligo-saccharides, (ii) carbohydrates, in particular starch and/or (iii)cellulose, as well as mixtures thereof.

Particularly preferred-component polymer fibers are those in which thethermoplastic polymer B is a polyolefin, in particular a polypropylenepolymer, which includes as additive B at least (i) metal compounds, inparticular transition metal compounds, as well as their salts,preferably at least two chemically different transition metal compoundsand (ii) unsaturated carboxylic acids or their anhydrides/esters/amides,preferably in combination with synthetic rubber and/or natural rubber,and—optionally—further comprising (iii) sugars, in particularmonosaccharides, disaccharides and oligosaccharides, (iv) carbohydrates,in particular starch and/or (v) cellulose, as well as mixtures thereof.Further, phenolic antioxidant stabilizer and CaO can be present.

The biological degradability can be fine-tuned by means of the quantityof additive A in component A or additive B in component B. The quantityof additive is usually between 0.005% by weight and 20% by weight,particularly preferably between 0.01% by weight and 5% by weight, withrespect to the total quantity of component A or component B.

Among the additives described above, the following in particular aresuitable: (i) basic alkali and/or alkaline earth compounds (pH>7dissolved in water), in particular carbonates, hydrogen carbonates,sulphates, particularly preferably CaCO3, (ii) sugars, in particularmono-saccharides, di-saccharides and oligo-saccharides, as well as (iii)carbohydrates, in particular starch and/or cellulose, as well asmixtures thereof, as well as the aforementioned combinations A), B) orC), because their degradability in accordance with ASTM D6691 or inaccordance with ASTM D5338-15, ASTM D6400 or ASTM D5988 can specificallybe adjusted.

Thermoplastic Polymers

The polymers used in accordance with the invention are thermoplasticpolymers.

The term “thermoplastic polymer” as used in the present invention meansa synthetic material which can be deformed in a specific range oftemperatures, preferably in the range 25° C. to 350° C.,(thermoplastic). This procedure is reversible, i.e. it can be put intoits viscous state any number of times by cooling and heating again, aslong as the material is not damaged too much by overheating, whichcauses what is known as thermal decomposition, or by shaping thematerial under mechanical load. This is the difference betweenthermoplastic polymers and thermosets and elastomers.

The thermoplastic polymers used in accordance with the invention arepreferably polymers selected from the group formed byacrylonitrile-ethylene-propylene-(diene)-styrene copolymer,acrylonitrile-methacrylate copolymer, acrylonitrile-methylmethacrylatecopolymer, chlorinated acrylonitrile, polyethylene-styrene copolymer,acrylonitrile-butadiene-styrene copolymer,acrylonitrile-ethylene-propylene-styrene copolymer, celluloseacetobutyrate, cellulose acetopropionate, hydrated cellulose,carboxymethylcellulose, cellulose nitrate, cellulose propionate,cellulose triacetate, polyvinyl chloride, ethylene-acrylic acidcopolymer, ethylene-butylacrylate copolymer,ethylene-chlorotrifluoroethylene copolymer, ethylene-ethlyacrylatecopolymer, ethylene-methacrylate copolymer, ethylene-methacrylic acidcopolymer, ethylene-tetrafluoroethylene copolymer, ethylene-vinylalcohol copolymer, ethylene-butene copolymer, ethylcellulose,polystyrene, polyfluoroethylene-propylene,methylmethacrylate-acrylonitrile-butadiene styrene copolymer,methylmethacrylate-butadiene-styrene copolymer, methylcellulose,polyamide 11, polyamide 12, polyamide 46, polyamide 6, polyamide 6-3-T,polyamide 6-terephthalic acid copolymer, polyamide 66, polyamide 69,polyamide 610. polyamide 612, polyamide 61, polyamide MXD 6, polyamidePDA-T, polyamide, polyarylether, polyaryletherketone, polyamideimide,polyarylamide, polyamino-bis-maleimide, polyarylate, polybutene-1,polybutylacrylate, polybenzimidazole, poly-bis-maleimide,polyoxadiazobenzimidazole, polybutylterephthalate, polycarbonate,polychlorotrifluoroethylene, polyethylene, polyestercarbonate,polyaryletherketone, polyetheretherketone, polyetherimide,polyetherketone, polyethylene oxide, 11polyarylether sulphone,polyethylene terephthalate, polyimide, polyisobutylene,polyisocyanurate, polyimide sulphone, polymethacrylimide,polymethacrylate, poly-4-methylpentene, polyacetal, polypropylene,polyphenyl oxide, polypropylene oxide, polyphenylene sulphide,polyphenylene sulphone, polystyrene, polysulphone,polytetrafluoroethylene, polyurethane, polyvinyl acetate, polyvinylalcohol, polyvinylbutyral, polyvinyl chloride, polyvinylidene chloride,polyvinylidene fluoride, polyvinyl fluoride, polyvinyl methyl ether,polyvinylpyrrolidone, styrene-butadiene copolymer, styrene-isoprenecopolymer, styrene-maleic acid anhydride copolymer, styrene-maleic acidanhydride-butadiene copolymer, styrene methyl methacrylate copolymer,styrene-methyl styrene copolymer, styrene-acrylonitrile copolymer, vinylchloride-ethylene copolymer, vinyl chloride-methacrylate copolymer,vinyl chloride-maleic acid anhydride copolymer, vinyl chloride-maleimidecopolymer, vinyl chloride-methylmethacrylate copolymer, vinylchloride-octyl acrylate copolymer, vinyl chloride-vinyl acetatecopolymer, vinyl chloride-vinylidene chloride copolymer, vinylchloride-vinylidene chloride-acrylonitrile copolymer.

Among the thermoplastic polymers, melt spinnable synthetic biopolymersare preferred, particularly preferably polycondensates and polymerisatesproduced from bio-based starting materials.

The term “synthetic biopolymer” as used in the present inventiondesignates a substance which primarily consists of biogenic rawmaterials(sustainable raw materials). This differentiates them fromconventional mineral oil-based substances or plastics such as, forexample, polyethylene (PE), polypropylene (PP) and polyvinyl chloride(PVC), as long as their feedstock is not renewable (e.g. bio-PE/greenPE).

In a preferred embodiment, the multi-component fibres in accordance withthe invention are produced from biologically degradable syntheticbiopolymers, wherein the term “biologically degradable” may, forexample, be specified, tested and/or determined in accordance with atleast one method selected from the group formed by (i) ASTM D5338-15(2021) (Standard Test Method for Determining Aerobic Biodegradation ofPlastic Materials Under Controlled Composting Conditions, IncorporatingThermophilic Temperatures (DOI:10.1520/D5338-15R21) ASTM International,West Conshohocken, P A, 2015, www.astm.org), (ii) ASTM D6400-12(Standard Specification for Labelling of Plastics Designed to beAerobically Composted in Municipal or Industrial Facilities) (DOI:10.1520/D6400-12), (iii) ASTM D5511 (ASTM D5511-11 Standard Test Methodfor Determining Anaerobic Biodegradation of Plastic Materials UnderHigh-Solids Anaerobic digestion Conditions (DOI: 10.1520/D5511-11) andASTM D5511-18 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-SolidsAnaerobic-digestion Conditions; (DOI: 10.1520/D5511-18)), (iv) ASTMD6691 (ASTM D6691-09 Standard Test Method for Determining AerobicBiodegradation of Plastic Materials in the Marine Environment by aDefined Microbial Consortium or Natural Sea Water Inoculum) (DOI:10.1520/D6691-09) and ASTM D6691-17, Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in the MarineEnvironment by a Defined Microbial Consortium or Natural Sea WaterInoculum (DOI: 10.1520/D6691-17)), (v) ASTM D5210-92 (AnaerobicDegradation in the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92),(vi) PAS 9017:2020 (Plastics— Biodegradation of polyolefins in anopen-air terrestrial environment—Specification), ISBN 978 0 539 17478 6;2021-10-31, (vii) ASTM D5988 (ASTM D5988-12 Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in Soil) (DOI:10.1520/D5988-12), ASTM D5988-18 Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials in Soil (DOI:10.1520/D5988-18), ASTM D5988-03 Standard Test Method for DeterminingAerobic Biodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), (viii) EN13432:2000-12 Packaging—Requirements for packaging recoverable throughcomposting and biodegradation—Test scheme and evaluation criteria forthe final acceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS 83.080.01) Determination of the ultimateaerobic biodegradability of plastic materials under controlledcomposting conditions (Method by analysis of evolved carbon dioxide),(x) EN 14995:2007-03—Plastics—Evaluation of compostability (DOI:10.31030/9730527) or (xi) ISO 17088:2021-04 (Specifications forcompostable plastics) (ICS 83.080.01).

Preferred synthetic biopolymers in the context of the present inventionare aliphatic, araliphatic polyesters or copolyesters which are producedfrom polyols, and aliphatic and/or aromatic dicarboxylic acids or theirderivatives (anhydrides, esters) by polycondensation, wherein thepolyols may be substituted or unsubstituted, and the polyols may belinear or branched polyols.

Preferred polyols are polyols containing 2 to 8 carbon atoms,polyalkylene etherglycols containing 2 to 8 carbon atoms andcycloaliphatic diols containing 4 to 12 carbon atoms. Non-limitingexamples of polyols which may be used include ethylene glycol,diethylene glycol, propylene glycol, 1,3-propanediol,2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol,1, 4-butanediol, 1,5-pentanediol, 1,6-hexanediol, polyethylene glycol,diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol,1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol andtetraethylene glycol. Preferred polyols include 1,4-butanediol,1,3-propanediol, ethylene glycol, 1,6-hexanediol, diethylene glycol,isosorbitol and 1,4-cyclohexanedimethanol.

Preferred aliphatic dicarboxylic acids include substituted orunsubstituted, linear or branched, non-aromatic dicarboxylic acidsselected from the group formed by aliphatic dicarboxylic acidscontaining 2 to 12 carbon atoms and cycloaliphatic dicarboxylic acidscontaining 5 to 10 carbon atoms, wherein the cycloaliphatic dicarboxylicacids may also contain heteroatoms in the ring.

The substituted non-aromatic dicarboxylic acids typically contain 1 to 4substituents selected from halogens, C6-C10 aryl and C1-C4 alkoxy.Non-limiting examples of aliphatic and cycloaliphatic dicarboxylic acidsinclude maleic acid, succinic acid, glutaric acid, adipic acid, pimelicacid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaricacid, suberic acid, 1,3-cyclopentane dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 3-cyclohexanedicarboxylic acid, diglycolic acid,itaconic acid, maleic acid, 2,5-norbornane dicarboxylic acid.

Preferred aromatic dicarboxylic acids include substituted orunsubstituted aromatic dicarboxylic acids selected from the group formedby aromatic dicarboxylic acids containing 6 to 12 carbon atoms, whereinthese carboxylic acids may also comprise heteroatoms in the aromaticring and/or in the substituents.

The substituted aromatic dicarboxylic acids may typically contain 1 to 4substituents selected from halogens, C6-C10 aryl and C1-C4 alkoxy.Non-limiting examples of aromatic dicarboxylic acids include phthalicacid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acidand furan dicarboxylic acid.

The aforementioned aliphatic dicarboxylic acids may also be togetherwith the aforementioned aromatic dicarboxylic acids in the form ofcopolymers or terpolymers; non-limiting examplesarepolybutylene-adipate-terephthalate and bio-based PTA.

Particularly preferred synthetic biopolymers in the context of thepresent invention are aliphatic polyesters with repeat units of at least4 carbon atoms, for example polyhydroxyalkanoates such aspolyhydroxyvalerate and polyhydroxybutyrate-hydroxyvalerate copolymer,polycaprolactone, furan dicarboxylic acid, and succinate-based aliphaticpolymers (for example polybutylene succinate, polybutylene succinateadipate and polyethylene succinate). Special examples may be selectedfrom polyethylene oxalate, polyethylene malonate, polyethylenesuccinate, polypropylene oxalate, polypropylene malonate, polypropylenesuccinate, polybutylene oxalate, polybutylene malonate, polybutylenesuccinate and blends and copolymers of these compounds.

In particular, the preferred synthetic biopolymers are aliphaticpolyesters comprising repeat units of lactic acid (PLA), hydroxy fattyacid (PHF) (also designated as polyhydroxyalkanoate, PHA), in particularhydroxybutanoic acid (PHB) and succinate-based aliphatic polymers, forexample polybutylene succinate, polybutylene succinate adipate andpolyethylene succinate.

The “aliphatic polyesters” should be understood to mean those polyesterswhich typically have at least approximately 50% molar, preferably atleast approximately 60% molar, particularly preferably at leastapproximately 70% molar, particularly preferably at least 95% molaraliphatic monomers.

In the context of the present invention, moreover, thermoplasticpolymers with a glass transition temperature of more than −125° C.,advantageously more than −30° C., preferably more than 30° C.,particularly preferably more than 50° C., in particular more than 70°C., are extremely advantageous. In the context of a more particularlypreferred embodiment of the present invention, the glass transitiontemperature of the polymer is in the range −125° C. to 200° C., inparticular in the range −125° C. to 100° C.

Among the thermoplastic synthetic biopolymers, the glass transitiontemperature is preferably more than 20° C., advantageously more than 25°C., preferably more than 30° C., particularly preferably more than 35°C., in particular more than 40° C. In the context of a more particularlypreferred embodiment of the present invention, the glass transitiontemperature of the polymer is in the range 35° C. to 55° C., inparticular in the range 40° C. to 50° C.

Particularly preferred polyesters are PET with a glass transitiontemperature of at least 70° C., PLA with a glass transition temperaturein the range 40° C. to 70° C., PHA and PHB with a glass transitiontemperature in the range −40° C. to 62° C., PBS, as well as PBScopolymers such as PBSA with a glass transition temperature in therange−45° C. to 45° C. and polycaprolactone with a glass transitiontemperature in the range−75° C. to 45° C.

Polyesters, in particular polyethylene terephthalate, usually have amolecular weight corresponding to an intrinsic viscosity (IV) of 0.4 to1.4 (dl/g), measured for solutions in dichloroacetic acid at 25° C.

Particularly preferred polyesters are those such as PET, PEN, PLA, PBS,PEIT with a number average molecular weight (Mn), preferably determinedby gel permeation chromatography against polystyrene standards with anarrow distribution or by end group titration, of at least 20000 g/mol.Better still, the polydispersibility of these polymers is at least 1.7.

Polyesters of particular interest are those such as PET with a meltingpoint between 250° C. and 260° C.

Particularly interesting polyesters are those such as PET with a meltingenthalpy of (80%: 43 J/g; 100% crystal/theoretical): 115 J/g.

Polyesters of particular interest are those such as PET with acrystallization temperature of at least 125° C. and a crystallizationenthalpy (125° C.) of at least 31 J/g.

Polyesters of particular interest are those which are commerciallyavailable from Trevira GmbH, for example such as Trevira® T298.

Particularly preferred polyamides have a glass transition temperature inthe range 30° C. to 80° C., in particular in the range 35° C. to 65° C.,particularly preferably in the range 50° C. to 60° C., wherein thesevalues are intended for PA 6.6 and PA 6 in particular.

Polyamides of particular interest are those such as PA 6.6 and PA 6 witha number average molecular weight (Mn), preferably determined by gelpermeation chromatography against polystyrene standards with a narrowdistribution or by end group titration, of at least 10000 g/mol.

Polyamides of particular interest are those such as PA 6.6 and PA 6,with a melting point between 170° C. and 280° C., more preferablybetween 200° C. and 260° C. Polyamides of particular interest are thosesuch as PA 6.6 and PA 6 with a Crystal melting enthalpy (100% crystal)of 190° C.

Particularly interesting polyamides are those such as PA 6.6 and PA 6with a softening temperature of 204° C.

Commercially available polyamides such as Nylon, Perlon or Grilon are ofparticular interest.

Polyolefins of particular interest are those such as polyethylene (PE)or polypropylene (PP) hompolymers, as well as copolymers or terpolymerswhich comprise at least 50 mol % of ethylene and/or propylene repeatunits.

Polyethylenes of particular interest are low density polyethylene(LDPE), linear low density polyethylene (LLDPE), very low densitypolyethylene (VLDPE), ultra low density polyethylene (ULDPE), mediumdensity polyethylene (MDPE), polymethylpentene (PMP), polybutene-1(PB-1); ethylene-octene copolymers, stereoblock PP, olefin blockcopolymers, propylene-butane copolymers.

Particularly preferred polyolefins are PE with a glass transitiontemperature in the range −100° C. to −35° C. and PP with a glasstransition temperature in the range −10° C. to −5° C.

Polyethylenes of particular interest are those with a melting pointbetween 120° C. and 135° C. and polypropylene with a melting pointbetween 158° C. and 170° C.

Polyethylenes of particular interest are those with a crystal meltingenthalpy (100% crystal) of 290 J/g and polypropylene with a crystalmelting enthalpy of 190 J/g.

Commercially available polyolefins such as LDPE (PE Aspun 6834, Dow),HDPE (SKGC MK 910), PP (Braskem) such as Braskem HSP165G, are ofparticular interest.

Further suitable polymers are those which have a melting temperature ofmore than 50° C., advantageously at least 75° C., preferably more than150° C. Particularly preferably, the melting temperature is in the range120° C. to 285° C., in particular in the range 150° C. to 270° C.,particularly preferably in the range 175° C. to 270° C.

In this regard, the glass transition temperature and the meltingtemperature of the polymer are preferably determined by means ofDifferential Scanning calorimetry (DSC).

Particularly preferred synthetic biopolymers in accordance with theinvention are thermoplastic polycondensates based on what are known asbiopolymers, which contain the repeat units of lactic acid,hydroxybutyric acid, succinic acid, glycolic acid and/or furandicarboxylic acid, preferably lactic acid and/or glycolic acid, inparticular lactic acid. Polylactic acids are particularly preferred inthis regard.

A variety of high melting point synthetic biopolymers (melting pointbetween 110° C. and 270° C., preferably between 140° C. and 270° C.,more preferably between 180° C. and 270° C.), such as polyesters, may beused in the present invention, such as polyesteramides, modifiedpolyethylene terephthalate, polylactic acid (PLA), terpolymers based onpolylactic acid, polybutylene succinate, polyalkylene furanoate such asPEF, polyglycolic acid, polyalkylene carbonates (such as polyethylenecarbonate), polyhydroxyalkanoates (PHA) such as polyhydroxybutyrates(PHB), polyhydroxyvalerates (PHV) or polyhydroxybutyrate-hydroxyvaleratecopolymers (PHBV).

The term “polylactic acid” (PLA) should be understood here to meanpolymers which are constructed from lactic acid units. Such polylacticacids are usually produced by condensation of lactic acids, but are alsoobtained by ring-opening polymerization of lactides under suitableconditions.

Particularly suitable polylactic acids in accordance with the inventioninclude poly(glycolide-co-L-lactide), poly(L-lactide),poly(L-lactide-co-caprolactone), poly(L-lactide-co-glycolide),poly(L-lactide-co-D,L-lactide), poly(D,L-lactide-co-glycolide) as wellas poly(dioxanone). As an example, polymers of this type arecommercially available fromBoehringer Ingelheim Pharma KG (Germany)under the trade names Resomer® GL 903, Resomer® L 206 S, Resomer® L 207S, Resomer® L 209 S, Resomer® L 210, Resomer® L 210 S, Resomer® LC 703S, Resomer® LG 824 S, Resomer® LG 855 S, Resomer® LG 857 S, Resomer® LR704 S, Resomer® LR 706 S, Resomer® LR 708, Resomer® LR 927 S, Resomer®RG 509 S and Resomer® X 206 S from Biomer, Inc. (Germany) with the nameBiomer(™) L9000. Other suitable polylactic acid polymers arecommercially available from Natureworks, LLC, Minneapolis, Minnesota,USA.

Especially advantageous polylactic acids for the purposes of the presentinvention are poly-D-, poly-L- or poly-D, L-lactic acids in particular.

The expression “polylactic acid” generally refers to homopolymers oflactic acid such as poly (L-lactic acid), poly (D-lactic acid), poly(DL-lactic acid), mixtures thereof and copolymers, which contain lacticacid as the primary component and a small proportion, preferably lessthan 10% molar, of a co-polymerizable co-monomer.

Further suitable materials are copolymers or terpolymers based onpolylactic acid, polyglycolic acid, polyalkylene carbonates (such aspolyethylene carbonate), polyhydroxyalkanoates (PHA),polyhydroxybutyrates (PHB), polyhydroxyvalerates (PHV) andpolyhydroxybutyrate-hydroxyvalerate copolymers (PHBV).

In a particularly preferred embodiment, the biopolymer is exclusively athermoplastic polycondensate based on lactic acids.

The polylactic acids used in accordance with the invention preferablyhave a number average molecular weight (Mn) which is a minimum of 500g/mol, preferably a minimum of 1000 g/mol, particularly preferably aminimum of 5000 g/mol, appropriately a minimum of 10000 g/mol, inparticular a minimum of 25000 g/mol. On the other hand, the numberaverage is preferably a maximum of 1000000 g/mol, appropriately amaximum of 500000 g/mol, advantageously a maximum of 100000 g/mol, inparticular a maximum of 50000 g/mol. A number average molecular weightin the range from a minimum of 10000 g/mol to 500000 g/mol has proved tobe particularly advantageous in the context of the present invention.

The mass average molecular weight (Mw) of preferred lactic acidpolymers, in particular of poly-D-, poly-L- or poly-D,L-lactic acids, ispreferably in the range 750 g/mol to 5000000 g/mol, preferably in therange 5000 g/mol to 1000000 g/mol, particularly preferably in the range10000 g/mol to 500000 g/mol, in particular in the range 30000 g/mol to500000 g/mol, and the polydispersity of these polymers is advantageouslyin the range 1.5 to 5.

The inherent viscosity of particularly suitable lactic acid polymers,poly-D-, poly-L- or poly-D,L-lactic acids in particular, measured inchloroform at 25° C., 0.1% polymer concentration, is in the range 0.5dl/g to 8.0 dl/g, preferably in the range 0.8 dl/g to 7.0 dl/g, inparticular in the range 1.5 dl/g to 3.2 dl/g.

Furthermore, the inherent viscosity of particularly suitable lactic acidpolymers, in particular poly-D-, poly-L- or poly-D,L-lactic acids,measured in hexafluoro-2-propanol at 30° C., at 0.1% polymerconcentration, is in the range from 1.0 dl/g to 2.6 dl/g, in particularin the range from 1.3 dl/g to 2.3 dl/g.

Of particular interest are polylactic acids with a glass transitiontemperature between 50° C. and 65° C.

Of particular interest are polylactic acids with a melting point between155° C. and 180° C.

Of particular interest are commercially available polylactic acids suchas NatureWorks PLA 6202D.

The term “polyhydroxy fatty acid esters” (PHF) as used in the context ofthe invention should preferably be understood to mean the followingpolymers: poly(3-hydroxypropionate) (PHP), poly(3-hydroxybutyrate) (PHB,P3HB), poly(3-hydroxyvalerate) (PHV), poly(3-hydroxyhexanoate) (PHHx),poly(3-hydroxyheptanoate) (PHH), poly(3-hydroxyoctanoate (PHO),poly(3-hydroxynonanoate) (PHN), poly(3-hydroxydecanoate) (PHD),poly(3-hydroxyundecanoate) (PHUD), poly(3-hydroxydodecanoate) (PHDD),poly(3-hydroxytetradecanoate) (PHTD), poly(3-hydroxypentadecanoate)(PHPD), poly(3-hydroxyhexadecanoate) (PHHxD) as well as blends of theaforementioned polymers. In addition to the aforementioned homopolymers,polyhydroxy fatty acid ester copolymers such aspoly(3-hydroxypropionate-co-3-hydroxybutyrate) (P3HP-3H B),poly(3-hydroxypropionate-co-4-hydroxybutyrate) (P3HP-4HB),poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P (3H B-4H B)),poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV),poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate)(PHBV-HHx) as well as blends of the aforementioned copolymers, may beused together or with the aforementioned homopolymers.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention are commercially available; examples areMirel, Biomer P 209, Biopol, Aonilex X, Proganic.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a glass transitiontemperature in the range −2° C. to 62° C.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a melting temperature inthe range 100° C. to 177° C.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a melt flow index (MFI) of5-10 g/10 min (190° C., 2.16 kg) determined in accordance with ISO1133-1:2011.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a number average molecularweight (Mn) of at least 200000 Dalton, in particular at least 220000Dalton, particularly preferably at least 250000 Dalton, and a maximum ofup to 3000000 Dalton, in particular up to 2500000 Dalton, particularlypreferably up to 2000000 Dalton.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention usually have a mass average molecularweight (Mw) which is about a factor of 2, preferably a factor of 3,times the number average molecular weight (Mn).

The term “succinate-based aliphatic polymers” should be understood tomean polymers with the following general formula:

wherein R1, R2, R3, R4 represent linear or branched aliphatichydrocarbon residues consisting of 2 to 20 carbon atoms. Examples inthis regard are polybutylene succinate, polybutylene succinate adipateand polyethylene succinate.

The thermoplastic succinate-based aliphatic polymers used in accordancewith the invention are commercially available; examples are Bionolle1000, BioPBS.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a glass transition temperature in the range−45° C. to 45° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a crystallization temperature in the range 70°C. to 90° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a melting temperature in the range 60° C. to180° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a melt flow index (MFI) of 5-10 g/10 min (190°C., 2.16 kg), determined in accordance with ISO 1133-1:2011.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a number average molecular weight (Mn) of atleast 20000 Dalton, in particular at least 30000 Dalton, particularlypreferably at least 35000 Dalton, and a maximum of up to 140000 Dalton,in particular up to 120000 Dalton, particularly preferably up to 110000Dalton.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a mass average molecular weight (Mw) which isabout a factor of 2, preferably a factor of 3, times the number averagemolecular weight (Mn).

Polycaprolactone (PCL) is a synthetic biopolymer within the meaning ofthe present invention.

Of particular interest are polycaprolactones with a glass transitiontemperature between −45° C. and 45° C.

Of particular interest are polycaprolactones with a crystallizationtemperature between 70° C. and 90° C.

Of particular interest are polycaprolactones with a melting pointbetween 60° C. and 180° C.

Of particular interest are polycaprolactones with a melting enthalpy of70-145 J/g.

Of particular interest are polycaprolactones with a number averagemolecular weight (Mn), preferably determined by gel permeationchromatography against polystyrene standards with a narrow distributionor by end group titration, of at least 20000 Dalton to 140000 Dalton.

Of particular interest are commercially available polycaprolactones suchas Resomer C 209.

Thermoplastic polymer A

The thermoplastic polymer A is selected from the aforementioned group ofthermoplastic polymers.

Among the thermoplastic polymers A, melt spinnable synthetic biopolymersare preferred, particularly preferably polycondensates and polymerisatesproduced from bio-based starting materials. The synthetic biopolymer isselected from the aforementioned group of synthetic biopolymers.

Preferred synthetic biopolymers are aliphatic, araliphatic polyesters orcopolyesters which are produced from polyols, and aliphatic and/oraromatic dicarboxylic acids or their derivatives (anhydrides, esters) bypolycondensation, wherein the polyols may be substituted orunsubstituted, linear or branched polyols.

Preferred polyols are polyols containing 2 to 8 carbon atoms,polyalkylene etherglycols containing 2 to 8 carbon atoms andcycloaliphatic diols containing 4 to 12 carbon atoms. Non-limitingexamples of polyols which may be used are ethylene glycol, diethyleneglycol, propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol,2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, polyethylene glycol, diethylene glycol,2,2,4-trimethyl-1,6-hexanediol, thiodiethanol,1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol andtetraethylene glycol. Preferred polyols include 1,4-butanediol,1,3-propanediol, ethylene glycol, 1,6-hexanediol, diethylene glycol,isosorbitol and 1,4-cyclohexanedimethanol.

Preferred aliphatic dicarboxylic acids include substituted orunsubstituted, linear or branched, non-aromatic dicarboxylic acidsselected from the group formed by aliphatic dicarboxylic acidscontaining 2 to 12 carbon atoms and cycloaliphatic dicarboxylic acidscontaining 5 to 10 carbon atoms, wherein the cycloaliphatic dicarboxylicacids may also contain heteroatoms in the ring.

The substituted non-aromatic dicarboxylic acids typically contain 1 to 4substituents selected from halogens, C6-C10 aryl and C1-C4 alkoxy.Non-limiting examples of aliphatic and cycloaliphatic dicarboxylic acidsinclude maleic acid, succinic acid, glutaric acid, adipic acid, pimelicacid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaricacid, suberic acid, 1,3-cyclopentane dicarboxylic acid,1,4-cyclohexanedicarboxylic acid, 3-cyclohexanedicarboxylic acid,diglycolic acid, itaconic acid, maleic acid, 2,5-norbornane dicarboxylicacid.

Preferred aromatic dicarboxylic acids include substituted orunsubstituted, aromatic dicarboxylic acids selected from the groupformed by aromatic dicarboxylic acids containing 6 to 12 carbon atoms,wherein these carboxylic acids may also comprise heteroatoms in thearomatic ring and/or in the substituents.

The substituted aromatic dicarboxylic acids may typically have 1 to 4substituents selected from halogens, C6-C10 aryl and C1-C4 alkoxy.Non-limiting examples of aromatic dicarboxylic acids include phthalicacid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acidand furan dicarboxylic acid.

Together with the aforementioned aromatic dicarboxylic acids, theaforementioned aliphatic dicarboxylic acids may also be present in theform of copolymers or terpolymers; non-limiting examples arepolybutylene-adipate terephthalate and bio-based PTA, for example.

Among the thermoplastic polymers A, preferred melt spinnable syntheticbiopolymers are aliphatic polyesters with repeat units of at least 4carbon atoms, for example polyhydroxyalkanoates such aspolyhydroxyvalerate and polyhydroxybutyrate-hydroxyvalerate copolymer,polycaprolactone, furan dicarboxylic acid, and succinate-based aliphaticpolymers (for example polybutylene succinate, polybutylene succinateadipate and polyethylene succinate). Special examples may be selectedfrom polyethylene oxalate, polyethylene malonate, polyethylenesuccinate, polypropylene oxalate, polypropylene malonate, polypropylenesuccinate, polybutylene oxalate, polybutylene malonate, polybutylenesuccinate and blends and copolymers of these compounds.

Particularly preferred synthetic biopolymers are aliphatic polyesterscomprising repeat units of lactic acid (PLA), hydroxy fatty acid (PHF)(also known as polyhydroxyalkanoate, PHA), in particular hydroxybutanoicacid (PHB) and succinate-based aliphatic polymers, for examplepolybutylene succinate, polybutylene succinate adipate and polyethylenesuccinate.

“Aliphatic polyesters” should be understood to mean those polyesterswhich typically have at least approximately 50% molar, preferably atleast approximately 60% molar, particularly preferably at leastapproximately 70% molar, particularly preferably at least 95% molaraliphatic monomers.

Among the thermoplastic polymers A, thermoplastic polymers with a glasstransition temperature of more than −125° C., advantageously more than−30° C., preferably more than 30° C., particularly preferably more than50° C., in particular more than 70° C., are preferred. In the context ofa particularly preferred embodiment, the glass transition temperature ofthe polymer is in the range −125° C. to 200° C., in particular in therange −125° C. to 100° C.

Among the thermoplastic polymers A, thermoplastic synthetic biopolymerswhich are preferred are those with a glass transition temperature whichis preferably more than 20° C., advantageously more than 25° C.,preferably more than 30° C., particularly preferably more than 35° C.,in particular more than 40° C. In the context of a particularlypreferred embodiment, the glass transition temperature of the polymer isin the range 35° C. to 55° C., in particular in the range 40° C. to 50°C.

Particularly preferred polyesters are PET with a glass transitiontemperature of at least 70° C., PLA with a glass transition temperaturein the range 40° C. to 70° C., PHA and PHB with a glass transitiontemperature in the range −40° C. to 62° C., PBS as well as PBScopolymers such as PBSA with a glass transition temperature in therange−45° C. to 45° C. and polycaprolactone with a glass transitiontemperature in the range−75° C. to 45° C.

Polyesters, in particular polyethylene terephthalate, usually have amolecular weight corresponding to an intrinsic viscosity (IV) of 0.4 to1.4 (dl/g), measured for solutions in dichloroacetic acid at 25° C.

Polyesters of particular interest are those such as PET, PEN, PLA, PBS,PEIT with a number average molecular weight (Mn), preferably determinedby gel permeation chromatography against polystyrene standards with anarrow distribution or by end group titration, of at least 20000 g/mol.Better still, the polydispersibility of these polymers is at least 1.7.

Polyesters of particular interest are those such as PET with a meltingpoint between 250° C. and 260° C.

Particularly interesting polyesters are those such as PET with a meltingenthalpy of (80%: 43 J/g; 100% crystal/theoretical): 115 J/g.

Polyesters of particular interest are those such as PET with acrystallization temperature of at least 125° C. and a crystallizationenthalpy (125° C.) of at least 31 J/g.

Polyesters of particular interest are those which are commerciallyavailable from Trevira GmbH, for example such as Trevira® T298.

Particularly preferred polyamides have a glass transition temperature inthe range 30° C. to 80° C., in particular in the range 35° C. to 65° C.,particularly preferably in the range 50° C. to 60° C., wherein thesevalues are intended for PA 6.6 and PA 6 in particular.

Polyamides of particular interest are those such as PA 6.6 and PA 6 witha number average molecular weight (Mn), preferably determined by gelpermeation chromatography against polystyrene standards with a narrowdistribution or by end group titration, of at least 10000 g/mol.

Polyamides of particular interest are those such as PA 6.6 and PA 6,with a melting point between 170° C. and 280° C., more preferablybetween 200° C. and 260° C. Polyamides of particular interest are thosesuch as PA 6.6 and PA 6 with a crystallization melting enthalpy (100%crystal) of 190° C.

Particularly interesting polyamides are those such as PA 6.6 and PA 6with a softening temperature of 204° C.

Commercially available polyamides such as Nylon, Perlon or Grilon are ofparticular interest.

Polyolefins of particular interest are those such as polyethylene (PE)or polypropylene (PP) hompolymers, as well as copolymers or terpolymerswhich comprise at least 50 mol % of ethylene and/or propylene repeatunits.

Polyethylenes of particular interest are low density polyethylene(LDPE), linear low density polyethylene (LLDPE), very low densitypolyethylene (VLDPE), ultra low density polyethylene (ULDPE), mediumdensity polyethylene (MDPE), polymethylpentene (PMP), polybutene-1(PB-1); ethylene-octene copolymers, stereoblock PP, olefin blockcopolymers, propylene-butane copolymers.

Particularly preferred polyolefins are PE with a glass transitiontemperature in the range −100° C. to −35° C. and PP with a glasstransition temperature in the range −10° C. to −5° C.

Polyethylenes of particular interest are those with a melting pointbetween 120° C. and 135° C. and polypropylene with a melting pointbetween 158° C. and 170° C.

Polyethylenes of particular interest are those with a crystallizationmelting enthalpy (100% crystal) of 290 J/g and polypropylene with acrystallization melting enthalpy of 190 J/g. Of particular interest arecommercially available polyolefins such as LDPE (PE Aspun 6834, Dow),HDPE (SKGC MK 910), PP (Braskem).

Further suitable polymers are those which have a melting temperature ofmore than 50° C., advantageously at least 75° C., preferably of morethan 150° C. Particularly preferably, the melting temperature is in therange from 120° C. to 285° C., in particular in the range from 150° C.to 270° C., particularly preferably in the range from 175° C. to 270° C.

In this regard, the glass transition temperature and the meltingtemperature of the polymer are preferably determined by means ofDifferential Scanning calorimetry (DSC).

Particularly preferred synthetic biopolymers in accordance with theinvention are thermoplastic polycondensates based on what are known asbiopolymers, which contain the repeat units of lactic acid,hydroxybutyric acid, succinic acid, glycolic acid and/or furandicarboxylic acid, preferably lactic acid and/or glycolic acid, inparticular lactic acid. Polylactic acids are particularly preferred inthis regard.

A variety of high melting point synthetic biopolymers (melting pointbetween 110° C. and 270° C., preferably between 140° C. and 270° C.,more preferably between 180° C. and 270° C.), such as polyesters, may beused in the present invention, such as polyesteramides, modifiedpolyethylene terephthalate, polylactic acid (PLA), terpolymers based onpolylactic acid, polybutylene succinate, polyalkylene furanoate such asPEF, polyglycolic acid, polyalkylene carbonates (such as polyethylenecarbonate), polyhydroxyalkanoates (PHA) such as polyhydroxybutyrate(PHB), polyhydroxyvalerate (PHV) or polyhydroxybutyrate-hydroxyvaleratecopolymers (PHBV).

The term “polylactic acid” (PLA) should be understood to mean polymerswhich are constructed from lactic acid units. Such polylactic acids areusually produced by condensation of lactic acids, but are also obtainedby ring-opening polymerization of lactides under suitable conditions.Particularly suitable polylactic acids in accordance with the inventioninclude poly(glycolide-co-L-lactide), poly(L-lactide),poly(L-lactide-co-□-caprolactone), poly(L-lactide-co-glycolide),poly(L-lactide-co-D,L-lactide), poly(D,L-lactide-co-glycolide) as wellas poly(dioxanone). As an example, polymers of this type arecommercially available from Boehringer Ingelheim Pharma KG (Germany)under the trade names Resomer® GL 903, Resomer® L 206 S, Resomer® L 207S, Resomer® L 209 S, Resomer® L 210, Resomer® L 210 S, Resomer® LC 703S, Resomer® LG 824 S, Resomer® LG 855 S, Resomer® LG 857 S, Resomer® LR704 S, Resomer® LR 706 S, Resomer® LR 708, Resomer® LR 927 S, Resomer®RG 509 S and Resomer® X 206 S, from Biomer, Inc. (Germany) with the nameBiomer(™) L9000. Other suitable polylactic acid polymers arecommercially available from Natureworks, LLC, Minneapolis, Minnesota,USA.

Especially advantageous polylactic acids for the purposes of the presentinvention are poly-D-, poly-L- or poly-D,L-lactic acids in particular.

The expression “polylactic acid” generally refers to homopolymers oflactic acid such as z. y (L-lactic acid), poly (D-lactic acid), poly(DL-lactic acid), mixtures thereof and copolymers which contain lacticacid as the primary component and a small proportion, preferably lessthan 10% molar, of a co-polymerizable co-monomer.

Further suitable materials are copolymers or terpolymers based onpolylactic acid, polyglycolic acid, polyalkylene carbonates (such aspolyethylene carbonate), polyhydroxyalkanoates (PHA),polyhydroxybutyrates (PHB), polyhydroxyvalerates (PHV) andpolyhydroxybutyrate-hydroxyvalerate copolymers (PHBV).

In a particularly preferred embodiment, the biopolymer is exclusively athermoplastic polycondensate based on lactic acids.

The polylactic acids used in accordance with the invention preferablyhave a number average molecular weight (Mn) which is a minimum of 500g/mol, preferably a minimum of 1000 g/mol, particularly preferably aminimum of 5000 g/mol, appropriately a minimum of 10000 g/mol, inparticular a minimum of 25000 g/mol. On the other hand, the numberaverage is preferably a maximum of 1000000 g/mol, appropriately amaximum of 500000 g/mol, advantageously a maximum of 100000 g/mol, inparticular a maximum of 50000 g/mol. A number average molecular weightin the range from a minimum of 10000 g/mol to 500000 g/mol has proved tobe particularly advantageous in the context of the present invention.

The mass average molecular weight (Mw) of preferred lactic acidpolymers, in particular of poly-D-, poly-L- or poly-D, L-lactic acids,is preferably in the range 750 g/mol to 5000000 g/mol, preferably in therange 5000 g/mol to 1000000 g/mol, particularly preferably in the range10000 g/mol to 500000 g/mol, in particular in the range 30000 g/mol to500000 g/mol, and the polydispersity of these polymers is advantageouslyin the range 1.5 to 5.

The inherent viscosity of particularly suitable lactic acid polymers,poly-D-, poly-L- or poly-D,L-lactic acids in particular, measured inchloroform at 25° C., 0.1% polymer concentration, is in the range 0.5dl/g to 8.0 dl/g, preferably in the range 0.8 dl/g to 7.0 dl/g, inparticular in the range 1.5 dl/g to 3.2 dl/g.

Furthermore, the inherent viscosity of particularly suitable lactic acidpolymers, in particular poly-D-, poly-L- or poly-D,L-lactic acids,measured in hexafluoro-2-propanol at 30° C., at 0.1% polymerconcentration, is in the range from 1.0 dl/g to 2.6 dl/g, in particularin the range from 1.3 dl/g to 2.3 dl/g.

Of particular interest are polylactic acids with a glass transitiontemperature between 50° C. and 65° C.

Of particular interest are polylactic acids with a melting point between155° C. and 180° C.

Of particular interest are commercially available polylactic acids suchas NatureWorks PLA 6202D.

The term “polyhydroxy fatty acid esters” (PHF) as used in the context ofthe invention should be understood to mean the following polymers:poly(3-hydroxypropionate) (PHP), poly(3-hydroxybutyrate) (PHB, P3HB),poly(3-hydroxyvalerate) (PHV), poly(3-hydroxyhexanoate) (PHHx),poly(3-hydroxyheptanoate) (PHH), poly(3-hydroxyoctanoate (PHO),poly(3-hydroxynonanoate) (PHN), poly(3-hydroxydecanoate) (PHD),poly(3-hydroxyundecanoate) (PHUD), poly(3-hydroxydodecanoate) (PHDD),poly(3-hydroxytetradecanoate) (PHTD), poly(3-hydroxypentadecanoate)(PHPD), poly(3-hydroxyhexadecanoate) (PHHxD) as well as blends of theaforementioned polymers. In addition to the aforementioned homopolymers,polyhydroxy fatty acid ester copolymers such aspoly(3-hydroxypropionate-co-3-hydroxybutyrate) (P3HP-3HB),poly(3-hydroxypropionate-co-4-hydroxybutyrate) (P3HP-4HB),poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-4HB)),poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV),poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBV-H Hx) as well as blends of the aforementioned copolymers, may be usedtogether or with the aforementioned homopolymers.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention are commercially available; examples areMirel, Biomer P 209, Biopol, Aonilex X, Proganic.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a glass transitiontemperature in the range −2° C. to 62° C.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a melting temperature inthe range 100° C. to 177° C.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a melt flow index (MFI) of5-10 g/10 min (190° C., 2.16 kg) determined in accordance with ISO1133-1:2011.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention preferably have a number average molecularweight (Mn) of at least 200000 Dalton, in particular at least 220000Dalton, particularly preferably at least 250000 Dalton, and a maximum ofup to 3000000 Dalton, in particular up to 2500000 Dalton, particularlypreferably up to 2000000 Dalton.

The thermoplastic polyhydroxy fatty acid ester polymers used inaccordance with the invention usually have a mass average molecularweight (Mw) which is about a factor of 2, preferably a factor of 3,times the number average molecular weight (Mn).

The term “succinate-based aliphatic polymers” should be understood tomean polymers with the following general formula:

wherein R1, R2, R3, R4 represent linear or branched aliphatichydrocarbon residues consisting of 2 to 20 carbon atoms.

Examples in this regard are polybutylene succinate, polybutylenesuccinate adipate and polyethylene succinate.

The thermoplastic succinate-based aliphatic polymers used in accordancewith the invention are commercially available; examples are Bionolle1000, BioPBS.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a glass transition temperature in the range−45° C. to 45° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a crystallization temperature in the range 70°C. to 90° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a melting temperature in the range 60° C. to180° C.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a melt flow index (MFI) of 5-10 g/10 min (190°C., 2.16 kg), determined in accordance with ISO 1133-1:2011.

The thermoplastic succinate polymers used in accordance with theinvention preferably have a number average molecular weight (Mn) of atleast 20000 Dalton, in particular at least 30000 Dalton, particularlypreferably at least 35000 Dalton, and a maximum of up to 140000 Dalton,in particular up to 120000 Dalton, particularly preferably up to 110000Dalton.

The thermoplastic succinate polymers used in accordance with theinvention usually have a mass average molecular weight (Mw) which isabout a factor of 2, preferably a factor of 3, times the number averagemolecular weight (Mn).

Polycaprolactone (PCL) is a synthetic biopolymer within the meaning ofthe present invention.

Of particular interest are polycaprolactones with a glass transitiontemperature between −45° C. and 45° C.

Of particular interest are polycaprolactones with a crystallizationtemperature between 70° C. and 90° C.

Of particular interest are polycaprolactones with a melting pointbetween 60° C. and 180° C.

Of particular interest are polycaprolactones with a melting enthalpy of70-145 J/g.

Of particular interest are polycaprolactones with a number averagemolecular weight (Mn), preferably determined by gel permeationchromatography against polystyrene standards with a narrow distributionor by end group titration, of at least 20000 Dalton to 140000 Dalton.

Of particular interest are commercially available polycaprolactones suchas Resomer C 209.

Thermoplastic Polymer B

The thermoplastic polymer B is selected from the aforementioned group ofthermoplastic polymers and preferred embodiments of thermoplasticpolymer B correspond to the preferred embodiments of thermoplasticpolymer A, as described above.

In a preferred embodiment, at least the thermoplastic polymer A and/orthe thermoplastic polymer B is/are selected from the group formed by themelt spinnable synthetic biopolymer, wherein polycondensates andpolymerisates from bio-based starting materials are particularlypreferred. Insofar as both thermoplastic polymers A and B are selectedfrom the group formed by melt spinnable synthetic biopolymers, it ispreferable to select biopolymers which differ as regards their chemicalnature and/or as regards their melting points. In this embodiment, themulti-component polymer fibres are preferably bi-component fibres inwhich the component A forms the core and the component B forms theshell. Particularly preferably, the melting point of the thermoplasticpolymer in the component A is at least 5° C., preferably at least 10°C., higher than the melting point of the thermoplastic polymer in thecomponent B.

Additives A and B

The additives A and B increase the biological degradability of themulti-component polymer fibres in accordance with the invention, inparticular of the bi-component fibres in accordance with the invention,in that these additives increase the biological degradability of thethermoplastic polymer A and/or of the thermoplastic polymer B. Themulti-component polymer fibre in accordance with the invention, inparticular the preferred bi-component fibre, contains (i) at least oneadditive A in the component A, or (ii) at least one additive B in thecomponent B, or (iii) at least one additive A in the component A and atleast one additive B in the component B. When at least one additive A ispresent in the component A and at least one additive B is present in thecomponent B, the additive A and the additive B are different, or when atleast one additive A is present in the component A and at least oneadditive B is present in the component B, the additive A and theadditive B may also be identical, if the thermoplastic polymer A andthermoplastic polymer B are different. The term “different” in thecontext of this paragraph means that the substances differ at least asregards their chemical natures or as regards their physical natures oras regards their concentrations.

In particular, the additives A and B are:

-   -   basic alkali and/or alkaline earth compounds (pH>7 dissolved in        water), in particular carbonates, hydrogen carbonates,        sulphates, particularly preferably CaCO3, and alkaline        additives, particularly preferably CaO    -   aliphatic polyesters, preferably aliphatic polyesters having no        side chain carbon atoms, preferably polycaprolactone    -   fatty acid ester, preferably C1-C40-alkyl stearate, more        preferred C2-C20-alkyl stearate, most preferred ethyl stearate    -   sugars, in particular monosaccharides, disaccharides and        oligosaccharides    -   catalysts for transesterifications, in particular under basic        conditions    -   metal compounds, in particular transition metal compounds,        preferably at least two transition metal compounds, as well as        their salts    -   unsaturated carboxylic acids or their anhydrides/esters/amides    -   synthetic rubber, natural rubber    -   carbohydrates, in particular starch and/or cellulose as well as        mixtures of the aforementioned substances.

Multi-component polymer fibres, in particular bi-component polymerfibres, in which the thermoplastic polymer A and/or the thermoplasticpolymer B comprise(s) at least one polyester and the additive A and/oradditive B is/are selected from the group (i) basic alkali and/oralkaline earth compounds (pH>7 dissolved in water), in particularcarbonates, hydrogen carbonates, sulphates, particularly preferablyCaCO3, and alkaline additives, particularly preferably CaO, (ii)aliphatic polyester, (iii) fatty acid ester, preferably C1-C40-alkylstearate, more preferred C2-C20-alkyl stearate, most preferred ethylstearate, (iv) sugars, in particular monosaccharides, disaccharides andoligosaccharides, (v) catalysts for transesterifications, in particularunder basic conditions, (vi) carbohydrates, in particular starch and/orcellulose, as well as mixtures thereof, are preferred.

Particularly preferred-component polymerfibres are those in which thethermoplastic polymer A and/or the thermoplastic polymer B comprises atleast one polyester and the additive A and/or additive B is selectedfrom the group (i) basic alkali and/or alkaline earth compounds (pH>7dissolved in water), in particular carbonates, hydrogen carbonates,sulphates, particularly preferably CaCO3, and alkaline additives,particularly preferably CaO, (ii) aliphatic polyesters, (iii) fatty acidester, preferably C1-C40-alkyl stearate, more preferred C2-C20-alkylstearate, most preferred ethyl stearate, (iv) sugars, in particularmono-saccharides, di-saccharides and oligo-saccharides, (v) catalystsfor transesterifications, in particular under basic conditions, (vi)carbohydrates, in particular starch and/or cellulose, as well asmixtures thereof. The aforementioned aliphatic polyesters aredistinguished from the polyesters of the thermoplastic polymer A andpolymer B in respect of their chemical nature, i.e. the polyester of thethermoplastic polymer A and polymer B is an araliphatic polyester orcopolyester, which has been produced from polyols and aliphatic and/oraromatic dicarboxylic acids or their derivatives (anhydrides, esters) bymeans of polycondensation.

Particularly preferred additives A and/or additives B contain at leasttwo substances, wherein preferred combinations are:

-   -   A) basic alkali and/or alkaline earth compounds (pH>7 dissolved        in water), in particular carbonates, hydrogen carbonates,        sulphates, particularly preferably CaCO3, and alkaline        additives, particularly preferably CaO in combination with        catalysts for transesterifications, in particular under basic        conditions;    -   B) sugars, in particular mono-saccharides, di-saccharides and        oligo-saccharides, in combination with carbohydrates, in        particular starch and/or cellulose, as well as mixtures thereof;    -   C) aliphatic polyesters, optionally in combination with sugars,        in particular mono-saccharides, di-saccharides and        oligo-saccharides, or carbohydrates, in particular starch and/or        cellulose, as well as mixtures thereof;    -   D) fatty acid ester, preferably C1-C40-alkyl stearate, more        preferred C2-C20-alkyl stearate, most preferred ethyl stearate.

Most preferred additives A for partially aromatic “araliphatic”polyester or copolyester as thermoplastic polymer A are containing atleast

-   -   basic alkali and/or alkaline earth compounds (pH>7 dissolved in        water), in particular carbonates, hydrogen carbonates,        sulphates, particularly preferably CaCO3, and alkaline        additives, particularly preferably CaO in combination with        catalysts for transesterifications, in particular under basic        conditions;        and    -   aliphatic polyesters, especially aliphatic polyester having no        side chain carbon atoms, optionally in combination with (i)        sugars, in particular mono-saccharides, di-saccharides and        oligo-saccharides, (ii) carbohydrates, in particular starch        and/or (iii) cellulose, (iv) fatty acid ester, preferably        C1-C40-alkyl stearate, more preferred C2-C20-alkyl stearate,        most preferred ethyl stearate. as well as mixtures thereof.

Out of the aforementioned particularly preferred-component polymerfibresare those preferred in which the thermoplastic polymer A is polyesterand the thermoplastic polymer B is a polyester being different from thepolyester in polymer A, and preferably is a co-polyester, and—each— theadditive A and the additive B is independently selected from thecombination of

-   -   basic alkali and/or alkaline earth compounds (pH>7 dissolved in        water), in particular carbonates, hydrogen carbonates,        sulphates, particularly preferably CaCO3, and alkaline        additives, particularly preferably CaO in combination with        catalysts for transesterifications, in particular under basic        conditions;        and    -   aliphatic polyesters, especially aliphatic polyester having no        side chain carbon atoms, optionally in combination with (i)        sugars, in particular mono-saccharides, di-saccharides and        oligo-saccharides, (ii) carbohydrates, in particular starch        and/or (iii) cellulose, (iv) fatty acid ester, preferably        C1-C40-alkyl stearate, more preferred C2-C20-alkyl stearate,        most preferred ethyl stearate, as well as mixtures thereof.

In a particular preferred embodiment, the aforementioned fatty acidesters are present and not optionally.

Multi-component polymer fibres, in particular bi-component polymerfibres, in which the thermoplastic polymer A and/or the thermoplasticpolymer B comprise(s) at least one polyolefin and the additive A and/oradditive B is/are selected from the group (i) sugars, in particularmonosaccharides, disaccharides and oligosaccharides, (ii) metalcompounds, in particular transition metal compounds, as well as theirsalts, (iii) unsaturated carboxylic acids or theiranhydrides/esters/amides, (iv) synthetic rubber and/or natural rubber,(v) carbohydrates, in particular starch and/or cellulose, as well asmixtures thereof, are preferred. In particular preferred for polyolefinis additive A and/or additive B comprising (a) transition metalcompounds and (b) unsaturated carboxylic acids or their anhydrides,which are in particular preferred combined with (c) synthetic rubberand/or natural rubber and (d) starch.

Particularly preferred-component polymerfibres are those in which thethermoplastic polymer B is a polyolefin, in particular a polypropylenepolymer, which includes as additive B at least (i) metal compounds, inparticular transition metal compounds, as well as their salts,preferably at least two chemically different transition metal compoundsand (ii) unsaturated carboxylic acids or their anhydrides/esters/amides,preferably in combination with synthetic rubber and/or natural rubber,and—optionally— further comprising (iii) sugars, in particularmonosaccharides, disaccharides and oligosaccharides, (iv) carbohydrates,in particular starch and/or (v) cellulose, as well as mixtures thereof.Further, phenolic antioxidant stabilizer and CaO can be present.

Multi-component polymer fibres, in particular bi-component polymerfibres, in which the thermoplastic polymer A and/or the thermoplasticpolymer B comprise(s) at least one polyamide and the additive A and/oradditive B is/are selected from the group (i) basic alkali and/oralkaline earth compounds (pH>7 dissolved in water), in particularcarbonates, hydrogen carbonates, sulphates, particularly preferablyCaCO3, and alkaline additives, particularly preferably CaO, (ii)aliphatic polyester, (iii) fatty acid ester, preferably C1-C40-alkylstearate, more preferred C2-C20-alkyl stearate, most preferred ethylstearate, (iv) sugars, in particular monosaccharides, disaccharides andoligosaccharides, (v) catalysts for transesterifications, in particularunder basic conditions, (vi) metal compounds, in particular transitionmetal compounds, as well as their salts, (vii) unsaturated carboxylicacids or their anhydrides/esters/amides, (viii) synthetic rubber and/ornatural rubber, (ix) carbohydrates, in particular starch and/orcellulose, as well as mixtures thereof, are preferred.

The additive A is in a proportion with respect to the component A whichis preferably between 0.005% by weight and 20% by weight, particularlypreferably between 0.01% by weight and 5% by weight, with respect to thetotal weight of the component A.

The additive B is in a proportion with respect to the component B whichis preferably between 0.005% by weight and 20% by weight, particularlypreferably between 0.01% by weight and 5% by weight, with respect to thetotal weight of the component B.

In order to obtain a low proportion by weight as well as a distributionof the additive in the component, which is as uniform as possible, theadditives are preferably added to the polymer material in the extruderin the form of what is known as a masterbatch.

The term “masterbatch” should be understood to mean a granulate which isadded to the polymer melt during the spinning process. In this regard,the granulate has a polymeric support material as well as at least oneadditive.

In order to enable small quantities of additive to be added to thepolymer, preferably, the concentration of the additive/additives in themasterbatch is preferably tailored. Preferably, the dosage ofmasterbatch in the spinning process is between 0.1% by weight and 30% byweight, particularly preferably between 0.5% by weight and 15% byweight.

Thermobonding

For thermobonding, suitable thermoplastic polymers, copolymers andblends in particular, in particular thermoplastic biopolymers are thosewhich have a high degree of enthalpies of fusion and crystallization.Usually, the polymers B are selected in a manner such that they have adegree of crystallinity or a latent heat of fusion (delta Hf) of morethan approximately 25 joules per gram (“Jig”), particularly preferablymore than 35 Jig, in particular more than 50 J/g. The determination ofthe latent heat of melting (ΔHf), the latent heat of crystallization(ΔHC) and the crystallization temperature is carried out by means ofDifferential Scanning calorimetry (“DSC”) in particular in accordancewith ASTM D-3418 (ASTM D3418-15, Standard Test Method for TransitionTemperatures and Enthalpies of Fusion and Crystallization of Polymers byDifferential Scanning calorimetry, ASTM International, WestConshohocken, P A, 2015, www.astm.ord).

Further Additives to Thermoplastics A and B

The thermoplastic polymers, copolymers and blends described above, inparticular the biopolymers described above, have the usual additivessuch as antioxidants, inter alia.

Further usual additives are pigments, stabilizers, surfactants, waxes,flow promoters, solid solvents, plasticizers and other materials, forexample nucleating agents, which are added in order to improve theprocessability of the thermoplastic composition.

The multi-component fibres in accordance with the invention, inparticular the bi-component fibres in accordance with the invention, areconstituted by at least 90% by weight of thermoplastic polymers,copolymers, blends described above, in particular of thermoplasticbiopolymers, and typically have less than approximately 10% by weight,preferably less than approximately 8% by weight, particularly preferablyless than approximately 5% by weight of additives, in particular in theshell.

The multi-component fibres in accordance with the invention, inparticular the bi-component fibres in accordance with the invention, maybe continuous fibres, for example what are known as staple fibres, orcontinuous fibres (filaments).

Production of Multi-Component Fibres

After spinning into tow, the multi-component fibres, in particular thebi-component fibre in accordance with the invention, are combinedtogether and post-treated in a rolling mill using methods which areknown in principle, in particular drawn and optionally also crimped ortexturized.

When processed after the (filament) spinning process, themulti-component polymer fibres in accordance with the invention arecooled immediately after exiting the spinneret and drawn and depositedon a collecting belt or preferably wound onto bobbins. Further steps inparticular include drawing, texturizing and heat bonding of thefilaments.

The production of the multi-component fibres in accordance with theinvention, in particular of the bi-component fibres in accordance withthe invention, is carried out using methods and equipment which is knownto the person skilled in the art, and these have been described in theliterature, for example in Fourné (Synthetische Fasern [SyntheticFibres]; 1995, Chapter 4 and Chapter 5.2.).

A number of production methods are available for the production ofnonwovens. In the production of spunbonds, the intermediate step ofstaple fibre production is not carried out. In particular, themulti-component fibres are swirled directly after exiting thespinnerets, preferably by means of a stream of air, so that they aredeposited as a nonwoven. The production of spunbonds is known to theperson skilled in the art and has been described in the literature, forexample in Fourné (Synthetische Fasern [Synthetic Fibres]; 1995, Chapter5.5).

In order to improve the dispersibility or for the purposes of furtherprocessing in the secondary spinning unit, in particular into yarns, thefibre is preferably in the form of a staple fibre. The length of saidstaple fibres is not limited in principle, but in general is 2 to 200mm, preferably 3 to 120 mm, particularly preferably 4 to 60 mm.

The individual linear density of the multi-component fibres inaccordance with the invention, in particular of the bi-component fibresin accordance with the invention, preferably staple fibres, is between0.5 and 30 dtex, preferably 0.7 to 13 dtex. For some applications,linear densities between 0.5 and 3 dtex and fibre lengths of <10 mm, inparticular <8 mm, particularly preferably <6 mm, particularly preferably<5 mm, are particularly suitable.

The multi-component fibres in accordance with the invention, inparticular the bi-component fibres in accordance with the invention,preferably have a low hot air heat shrinkage in the range 0% to 10%,preferably >0% to 8%, respectively measured at 110° C.

The production of the polymer fibres in accordance with the invention isin principle carried out using the usual processes. Firstly, thepolymer, if necessary, is dried and supplied to an extruder. Next, themolten material is spun using the regular equipment with appropriatespinnerets. The mass throughput and the draw-off speed of thecapillaries from the spinneret outlet plates are set so that a fibrewith the desired linear density is produced.

The fibres formed may have different shapes, for example round, oval,star-shaped, dog-bone shaped, barbell-shaped, kidney-shaped, triangularor polygonal, cloverleaf-shaped, horseshoe-shaped, lens-shaped,rod-shaped, gearwheel-shaped, cloud-shaped, x-shaped, y-shaped,o-shaped, u-shaped; this list is not limiting and other suitable crosssections are also possible.

The fibre filaments produced in accordance with the invention arecollected into yarns and then in turn into tows. The tows are initiallydeposited into cans for further processing. The tows which aretemporarily stored in the cans are picked up and a large cable tow isproduced.

The present invention also concerns the post-treatment of the cable towproduced by means of the known process; usually, it is 10-600 ktex usingconventional rolling mills, and special drawing. An infeed speed for thecable tow into the drawing or drawing equipment is preferably 10 to 110m/m in (infeed speed). In this regard, other preparations may also beapplied which aid drawing but which do not have a deleterious effect onthe subsequent properties.

Drawing may be carried out in a single step or optionally using atwo-stage drawing process (see in this regard U.S. Pat. No. 3,816,486,for example). Prior to and during drawing, one or more finishing agentsmay be applied using conventional methods.

The drawing in accordance with the invention is carried out with a drawratio, in particular when biopolymers are used, of between 1.2 and 6.0,preferably between 2.0 and 4.0, wherein the temperature when drawing thetow is preferably between 30° C. and 100° C. Drawing is thus carried outin the glass transition temperature range for the tow to be drawn.Drawing in accordance with the invention is carried out in the presenceof steam, i.e. in what are known as steam boxes, so that the fibres aredrawn in the steam boxes. The steam boxes are normally operated under apressure of 3 bar.

By drawing in the presence of steam in the aforementioned temperaturerange, thermal shrinkage of the fibres can be reduced and controlled ina specific manner.

The tow is preferably 24-360 ktex prior to drawing.

Drawing is preferably in one stage or in multiple stages, wherein thegodets of the drawing unit may be at different temperatures and also thedraw ratios between the drawing unit may be different. Preferably, asteam box is positioned between at least two of the drawing units, i.e.the drawing point for the fibres is in the steam box or close to thesteam box. All of the godets (usually 7 per drawing unit) are at atemperature of 30-250° C. All of the drawing is preferably carried outat least partially or entirely in the steam box. Preferably, the steambox is operated at a pressure of 3 bar of steam.

Drawing may also be carried out cold, wherein “cold” means roomtemperature (approximately 20-35° C.).

Carrying out of the respective drawing as well as the choice of all ofthe parameters for the rolling mill is carried out as a function of thepolymer and/or the end use of the fibres.

For the optional crimping/texturizing of the drawn fibres, conventionalmethods of mechanical crimping with crimping machines which are knownper se may be used. Preferably, a mechanical device for fibre crimpingwith steam support is used, such as a stuffer box. However, crimpedfibres may be obtained using other processes, includingthree-dimensionally crimped fibres, for example. In order to carry outthe crimping, the tow is initially and usually brought to a constanttemperature in the range 50° C. to 100° C., preferably 70° C. to 85° C.,particularly preferably to approximately 78° C. and treated at apressure for the tow infeed rolls of 1.0 to 6.0 bar, particularlypreferably at approximately 2.0 bar, a pressure in the crimping box of0.5 to 6.0 bar, particularly preferably 1.5-3.0 bar, with steam at arate of between 1.0 and 2.0 kg/min, particularly preferably 1.5 kg/min.

If the smooth or optionally crimped fibres are relaxed and/or fixed inan oven or stream of hot air, this is also carried out at maximumtemperatures of 130° C.

In order to produce staple fibres, the smooth or optionally crimpedfibres are picked up, followed by cutting and depositing into compressedbales as flock. The staple fibres of the present invention arepreferably cut on a mechanical cutting device which is downstream ofrelaxation. In order to produce different types of tow, cutting may bedispensed with. These types of tow are deposited and compressed in theuncut form in bales.

When the fibres in accordance with the invention are in a crimpedembodiment, then the degree of crimping is preferably at least 2 crimps(arched crimps) per cm, preferably at least 3 crimps per cm, preferably3 crimps per cm to 9.8 crimps per cm and particularly preferably 3.9crimps per cm to 8.9 crimps per cm. In applications for the productionof textile fabrics, values for the degree of crimping of approximately 5to 5.5 crimps per cm are particularly preferred. For the production oftextile fabrics using wet laid processes, the degree of crimping has tobe set individually.

A typical set-up for producing bi-component fibre of the core/shell(=core/sheath) type having polyethylene terephthalate (PET) asthermoplastic polymer A and additive A in the core and polypropylene(PP) as thermoplastic polymer B and additive B in the shell (sheath)includes the following:

-   -   The PET raw material is dried, typically up to 4-6 h @ temp up        to 180° C.; Typically, polypropylene (PP) does not require        drying;    -   The melt extrusion is typically done extruders having one or        more screws;    -   The bicomponent spinneret configuration is concentric or        eccentric with PP as shell (sheath) material and PET as core        component;    -   The extruder melt temperatures for core is typically in the        range 250-300° C. for PET and for sheath material typically in        the range 220-270° C. for PP;    -   Additives added at extruder feed-throat for both shell (sheath)        and core at a level between 1-3 wt.-%, typically in the form of        a masterbatch;    -   Fibre Quench is typically crossflow and the air temperature is        typically in the range 18-24° C.;    -   typical fibre drawdown speeds are in the range 800-1300 m/min;    -   fibre drawing can be single or duo-stage drawing with draw ratio        up to 4 and heat setting at 110-130° C.

A typical set-up for producing bi-component fibre of the core/shell(=core/sheath) type having polyethylene terephthalate polymer (PET) asthermoplastic polymer A and additive A in the core and polyethyleneterephthalate copolymer (coPET) as thermoplastic polymer B and additiveB in the shell (sheath) includes the following:

-   -   The PET raw materials are dried, typically up to 4-6 h @ temp up        to 180° C.;    -   The melt extrusion is typically done extruders having one or        more screws, one extruder for shell (sheath) material (coPET)        and one for core material (PET);    -   The bicomponent spinneret configuration is concentric or        eccentric with coPET as shell (sheath) material and PET as core        component;    -   The extruder melt temperatures are typically in the range        250-300° C.;    -   Additives added at extruder feed-throat for both shell (sheath)        and core at a level between 1-3 wt.-%, typically in the form of        a masterbatch;    -   Fibre quench is typically crossflow or in-flow or radial        out-flow and the air temperature is typically in the range        18-50° C.;    -   typical fibre drawdown speeds are in the range 400-1800 m/min,        preferably 1400 m/m in;    -   fibre drawing can be single or duo-stage drawing with draw ratio        up to 4.5, specifically 2.5-3.5, finish bath temperature up to        80° C., godet temperatures up to 70° C., specifically 30° C.        before steam-bath if present, and temperature after stretch        point up to 80° C., heat setting, typically in a hot air oven,        at temperatures up to 190° C.

Textile fabrics can be produced from the fibres in accordance with theinvention; these also constitute the subject matter of the invention.

Textile Fabric

The term “textile fabric” as used in the context of this descriptionshould be construed in its broadest sense. Thus, they may be anystructure containing the fibres in accordance with the invention whichhave been produced using a technique for producing a fabric. Examples ofsuch textile fabrics are nonwovens, in particular wet laid nonwovens ordry laid nonwovens, preferably based on staple fibres which are producedby means of thermobonding. Other examples of nonwovens are carded orairlaid nonwovens, preferably based on staple fibres or nonwovens,produced using a melt blowing and/or spunbond filament process.Particularly in the case in which the fibres or nonwovens have a lowlinear density, meltblown processes (for example as described in“Complete Textile Glossary”, Celanese Acetate LLC, from 2000 or in“Chemiefaser-Lexikon, Robert Bauer, 10th edition, 1993) andelectrospinning processes are the most suitable.

In order to produce a nonwoven using the spunbond filament process, thefreshly spun fibres, preferably freshly spun bi-component fibres, arecollected on a collecting conveyor to lay them up to a specifiedthickness so that the spunbond nonwoven can be obtained. The spunbondnonwoven can be consolidated further, for example using the hotembossing process with the use of an embossing roller or using knownneedling/water jet processes, to further entangle the nonwoven. Whenbi-component fibres are used, wherein the bi-component fibres have ahigher and a lower melting point component, the nonwoven is consolidatedby means of thermobonding using the lower melting point component.

For the aforementioned thermobonding, the textile fabric which containsthe bi-component/multi-component fibres, is fed into an oven, forexample a ventilated dryer which contains one or more heating zoneswhich are used to heat the air to a temperature which is higher than themelting temperature of the lower melting point component (for examplethe shell) of the multi-component fibres, but lower than the meltingtemperature of the higher melting point component (for example thecore). This heated air flows through the textile fabric, typically anonwoven, whereupon the lower melting point component melts and formsbonds between the fibres in order to stabilize the fabric thermally.

Typically, the air flowing through the thermobonding oven is at atemperature in the range from 100□C to approximately 180□C. Theresidence time in the oven is approximately 180 seconds or less. Itshould be understood, however, that the parameters of the thermobondingoven are a function of the type of polymers used and the thickness ofthe material.

Ultrasound consolidation techniques may also be used, which employ astationary or rotating horn and a rotating patterned embossing roller.Examples of such techniques are described in U.S. Pat. Nos. 3,939,033;3,844,869; 4,259,399; 5,096,532; 5,110,403 and 5,817,199, which areincorporated herein by reference in their entirety for all purposes. Asan alternative, the nonwoven may be thermally spot welded in order toprovide a fabric with a great many small, discrete binding points. Thisprocess in general involves guiding the fabric between two heatedrollers such as, for example, a roller with an engraved pattern and asecond binding roller. The engraved roller is patterned in a manner suchthat the web is not bonded over its entire surface, and the secondroller may be smooth or patterned.

For functional and/or aesthetic reasons, a variety of patterns have beendeveloped for engraved rollers. Examples of binding patterns include butare not limited to those described in in U.S. Pat. Nos. 3,855,046;5,620,779; 5,962,112; 6,093,665; US patent of design, number 428 267 andUS patent of design, number 390 708, which are incorporated herein byreference in their entirety for all purposes.

The basis weight of the textile fabric, in particular the basis weightof the nonwoven, is between 10 and 500 g/m², preferably 25 to 450 g/m²,in particular 30 to 300 g/m².

The textile fabric which is produced from the multi-component fibres inaccordance with the invention, in particular from the bi-componentfibres in accordance with the invention, in particular nonwovens, can beproduced in a known manner using a calendar roller or can be thermallyconsolidated in an oven.

The textile fabric which is produced from the multi-component fibres inaccordance with the invention, for example nonwovens, are usuallyproduced by means of thermobonding because of the different meltingpoints of the components. This bonds the fibres together at the contactor crossover points.

Insofar as the component B produced from thermoplastic polymer B withadditive B has a higher biological degradability than the component Aproduced from thermoplastic polymer A with additive A, the contact orcrossover points of the fibres with each other are degraded first andthe textile fabric, for example a nonwoven, disintegrates faster,whereupon the overall degradability is increased.

Here, the textile fabrics, in particular the nonwovens, can—in additionto the multi-component fibres—comprise still other fibres, depending onthe intended purpose. In this regard, the “filler fibres” described inWO 2007/107906 should in particular be highlighted. The “filler fibres”described in WO 2007/107906 also form part of the subject matter of theinvention and are incorporated into the present invention.

The textile fabrics include the aforementioned biologically degradablepolymer material fibres which may be mixed with other fibrous materials,chemical fibres, preferably natural fibres such as cotton or cellulosefibres, fibres of animal origin such as wool or other biologicallydegradable fibres. When mixing such different fibres, textile fabricswith a fibre gradient may be produced. Examples of cellulose fibresinclude softwood kraft pulp fibres. Softwood kraft pulp fibres areobtained from conifers and include cellulose fibres such as, but notrestricted to, northern, western and southern softwood species such asredwood, red cedar, hemlock spruce, Douglas fir, true spruces, pinetrees (for example southern pine), spruce (for example black spruce),combinations thereof etc. In the present invention, northern softwoodkraft pulp fibres may be used. Another suitable cellulose material foruse in the present invention is a bleached sulphate wood cellulosematerial which primarily contains softwood fibres. Fibres with smalleraverage lengths may also be used in the present invention. An example ofsuitable cellulose material fiber with a low average length are hardwoodkraft pulp fibres. Hardwood kraft pulp fibres are derived from deciduoustrees and include cellulose material fibers such as, but not restrictedto eucalyptus, maple, beech, aspen etc. Eucalyptus kraft pulp fibres maybe particularly favored in order to increase softness, increase sheen,increase opacity and change the pore structure of the sheet in order toincrease its absorbency. Typically, cellulose material fibers make upapproximately 30% by weight to approximately 95% by weight, in someembodiments approximately 40% by weight to approximately 90% by weightand in some embodiments approximately 50% by weight to approximately 85%by weight of the nonwoven.

In addition, superabsorbent materials may also be contained in thenonwoven. Superabsorbent materials are materials which swell in waterwhich can absorb 20 times their weight and in some case at least 30times their weight in an aqueous solution containing 0.9% by weight ofsodium chloride. The superabsorbent materials may be natural, syntheticand modified natural polymers and materials. Examples of syntheticsuperabsorbent polymers include alkali metal and ammonium salts ofpoly(acrylic acid) and poly(methacrylic acid), poly(acrylamides),polyvinylethers), maleic acid anhydridecopolymers with vinyl ethers andalpha olefins, polyvinylpyrrolidone), poly(vinylmorpholinone),polyvinylalcohol) and mixtures and copolymers thereof. Othersuperabsorbent materials include natural and modified natural polymerssuch as hydrolysed acrylonitrile-grafted starches, acrylic acid-graftedstarches, methylcelluloses, chitosan, carboxymethylcelluloses,hydroxypropylcelluloses and natural gums such as alginates, xanthangums, carob bean gum etc. Mixtures of natural and completely orpartially synthetic superabsorbent polymers may also be useful in thepresent invention. When the superabsorbent material is used, it may makeup approximately 30% by weight to approximately 95% by weight, in someembodiments approximately 40% by weight to approximately 90% by weightand in some embodiments approximately 50% by weight to approximately 85%by weight of the nonwoven.

The present textile fabrics, in particular the aforementioned nonwoven,may be used in an absorbent article such as, for example, absorbentarticles for body care such as, for example, nappies, training pants,absorbent underwear, incontinence articles, sanitary wear for women, butnot restricted thereto (for example sanitary towels), swimwear, babywipes etc; medical absorbent articles such as clothing, windowmaterials, underlays, bed protectors, bandages, absorbent cloths andmedical wipes; wipes for the food industry; items of clothing, etc.Materials and processes which are suitable for the production ofabsorbent articles of this type are known to the person skilled in theart. Typically, absorbent articles comprise a substantiallyliquid-impermeable layer (for example the outer shell), aliquid-permeable layer (for example the layer facing the body), barrierlayered) and an absorbent core. The nonwoven in the present inventionmay be used as one or more of the liquid-impermeable, liquid-permeableand/or absorbent layers.

The present textile fabrics, in particular the nonwoven described above,are not limited to the aforementioned applications and may be used inany application such as, for example, in hygiene, medicine, personalprotection, in the household (fibre fill etc), clothing,mobility/transport (car, train, aircraft, shipping), engineering(insulation), agriculture, packaging, filtration and any disposableapplications.

Test Methods

Unless stated otherwise in the present description, the followingmeasurement or test methods were employed:

Linear density: The determination of the linear density was carried outin accordance with DIN EN ISO1973.

Biological degradability: The determinations, testing and specificationswere in accordance with at least one method selected from the groupformed by (i) ASTM D5338-15 (2021) (Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials Under Controlled CompostingConditions, Incorporating Thermophilic Temperatures(DOI:10.1520/D5338-15R21) ASTM International, West Conshohocken, P A,2015, www.astm.orq), (ii) ASTM D6400-12 (Standard Specification forLabeling of Plastics Designed to be Aerobically Composted in Municipalor Industrial Facilities) (DOI: 10.1520/D6400-12), (iii) ASTM D5511(ASTM D5511-11 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-Solids Anaerobicdigestion Conditions (DOI: 10.1520/D5511-11) and ASTM D5511-18 StandardTest Method for Determining Anaerobic Biodegradation of PlasticMaterials Under High-Solids Anaerobic-digestion Conditions; (DOI:10.1520/D5511-18)), (iv) ASTM D6691 (ASTM D6691-09 Standard Test Methodfor Determining Aerobic Biodegradation of Plastic Materials in theMarine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum) (DOI: 10.1520/D6691-09) and ASTM D6691-17, Standard TestMethod for Determining Aerobic Biodegradation of Plastic Materials inthe Marine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum (DOI: 10.1520/D6691-17)), (v) ASTM D5210-92 (AnaerobicDegradation in the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92),(vi) PAS 9017:2020 (Plastics—Biodegradation of polyolefins in anopen-air terrestrial environment—Specification), ISBN 978 0 539 17478 6;2021-10-31, (vii) ASTM D5988 (ASTM D5988-12 Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in Soil) (DOI:10.1520/D5988-12), ASTM D5988-18 Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials in Soil (DOI:10.1520/D5988-18), ASTM D5988-03 Standard Test Method for DeterminingAerobic Biodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), (viii) EN13432:2000-12 Packaging—Requirements for packaging recoverable throughcomposting and biodegradation—Test scheme and evaluation criteria forthe final acceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS83.080.01) Determination of the ultimate aerobicbiodegradability of plastic materials under controlled compostingconditions (Method by analysis of evolved carbon dioxide), (x) EN14995:2007-03— Plastics—Evaluation of compostability (DOI:10.31030/9730527) or (xi) ISO 17088:2021-04 (Specifications forcompostable plastics) (ICS 83.080.01).

Number and mass average molecular weight (Mn/Mw): Determination usinggel permeation chromatography against suitable polymer standards with anarrow distribution, in particular DIN 55672 (gel permeationchromatography (GPC)).

Inherent viscosity: Determination measured in chloroform at 25° C., 0.1%polymer concentration via GPC.

Glass transition temperature and melting temperature: In particular,determination of the glass transition temperature in accordance with DINEN ISO 11357-2:2020-08 (Plastics—Differential Scanning calorimetry(DSC)— Part 2: Determination of glass transition temperature and thestep height related to glass transition). In particular, determinationof the melting temperature in accordance with DIN EN ISO 11357-3:2018-07(Plastics—Differential Scanning calorimetry (DSC)—Part 3: Determinationof the temperatures and enthalpies of melting and crystallization).

Determination by means of Differential Scanning calorimetry (DSC) usingthe following protocol: DSC measurement carried out under nitrogen,calibration against indium. Nitrogen flow 50 mL/min; weight of fibres inthe range 2-3 mg.

Temperature range from −50° C. to 210° C. @ 10 K/min then isothermal for5 min and finally back up to −50° C. @ 10 K/min.

In general, the final temperature was always approximately 50° C. abovethe highest expected melting point. DSC measurement carried out using aTA/Waters Model Q100.

Melt viscosity: The melt viscosity was determined using a Göttfert RheoTester 1000 at a temperature suitable for the polymer, betweenapproximately 190° C. and 280° C. In particular, use of ASTM D2196-20(Standard Test Methods for Rheological Properties of Non-NewtonianMaterials by Rotational Viscometer).

Apparent viscosity: The determination was carried out as described in WO2007/070064.

Melt flow index: Determination in accordance with the ASTM test methodD1238-13 (ASTM D1238-13, Standard Test Method for Melt Flow Rates ofThermoplastics by Extrusion Plastometer, ASTM International, WestConshohocken, P A, 2013, www.astm.org) or in accordance with DIN EN ISO1133-1:2012-03 (Plastics—Determination of the melt mass-flow rate (MFR)and the melt volume flow-rate (MVR) of thermoplastics—Part 1: Standardtest method) and DIN EN ISO 1133-2:2012-03 (Plastics—Determination ofthe melt mass-flow rate (MFR) and the melt volume flow-rate (MVR) ofthermoplastics. Part 2: Procedure for materials which are sensitive totime-temperature history and/or to moisture). The melt flow index is theweight of a polymer (in grams) that can be pressed through an extrusionrheometer opening (for example 0.0825 inch diameter) when a force of2160 grams, for example, is applied over a period of 10 minutes, forexample, at 190° C., for example.

Latent heat of melting: Determinations of latent heat of melting (ΔHf),the latent heat of crystallization (ΔHC) and the crystallizationtemperature were carried out using Differential Scanning calorimetry(“DSC”) in accordance with ASTM D-3418 (ASTM D3418-15, Standard TestMethod for Transition Temperatures and Enthalpies of Fusion andCrystallization of Polymers by Differential Scanning calorimetry, ASTMInternational, West Conshohocken, P A, 2015, www.astm.org) or inaccordance with DIN EN ISO 11357 (Plastics—Differential Scanningcalorimetry (DSC)).

Heat shrinkage: 12 fibres (test specimens) were prepared from the samplecable tow. They were clamped at one end in a terminal block with the aidof tweezers, and a decrimping weight was fastened to the other end. Themeasurement was carried out with the aid of a bi-component fiber of thetype core/shell with a linear density of 2.2 dtex; the decrimping weightwas 190 mg.

The terminal block with the test specimens was fastened into a supportstand so that the test specimens were freely suspended in the supportstand under pre-tension.

The selected starting length (in normal cases 150 mm) was marked here oneach fibre. This was carried out with the aid of marking lines in thesupport stand and marking points applied to the test specimens. Aftermarking, the filled terminal block was picked up and replaced on theplate. Here, the decrimping weights were removed and the free fibre endswere clamped into a second terminal block. The test specimens spanningthe two terminal blocks were suspended in a wire frame, not undertension. This wire frame was introduced into the centre of the shrinkageoven preheated to the correct treatment temperature (usual temperaturesare 200° C., 110° C., 80° C.). After the treatment time of 5 min, thewire frame was removed from the oven. After a cooling period for theterminal blocks of at least 30 min, the terminal blocks with the testspecimens were removed from the frame and the fibres replaced on theplate. The back measurement could then be carried out. To this end, thetest specimens were once again loaded with the decrimping weights andsuspended in the support stand. For the back measurement, the adjustablemarking line of the support stand was positioned such that therespective upper edge of the marking point could cover the marking line.Then, for each individual fibre, the length between the marks could beread off from the counters on the support stand to an accuracy of 1/10mm.

${{Calculation}{of}{change}{of}{length}:{Change}{of}{{length}\lbrack\%\rbrack}} = {\frac{{{initial}{{lengt}\lbrack{mm}\rbrack}} - {{measure}{{length}\lbrack{mm}\rbrack}}}{{initial}{{length}\lbrack{mm}\rbrack}} \times 100\%}$

The average value for all 12 test specimens was used.

The invention will now be illustrated by the following examples, whichdoes not in any way limit its scope.

Example 1

A polyethylene terephthalate (PET) fibre is spun from a polyethyleneterephthalate (PET) resin having the following properties:

The melt extrusion is done by an extruder having one or more screws at atemperature of 280-290° C. for PET

Additive A is added at the extruder feed-throat at a level of 2 wt.-%masterbatch dosage. This masterbatch consists of a PET polyester ascarrier and the additive, which comprises an aliphatic polyester andCaCO3.

The fibre quench occurs by crossflow and air temperature of 40° C.;fibre drawdown speed is 1400 m/min, Spun fiber fineness is 5.4 dtex.

The fibre drawing is done by single or duo-stage drawing with draw ratioup to 4 and the final dtex is 2.5 dtex. Heat setting is done at 110-130°C.

The fibre produced is cut into staple fibre having a length of 38 mm.The fibre produced is tested in accordance with ASTM D5511 and resultsare obtained after 208 days as shown below in Table 1:

TABLE 1 The biodegradation is shown in FIG. 1 versus the control. 3066 -PET Staple Fibre with biodegrative Inculum Negative Positive additiveCumulative 1366.6 1229.3 9867.0 6356.4 Gas Volume (mL) Percent CH4 40.731.7 37.4 45.5 (%) Volume CH4 556.0 390.1 3693.0 2890.6 (mL) Mass CH4(g) 0.40 0.28 2.64 2.06 Percent CO2 41.0 40.5 43.6 38.0 (%) Volume CO2560.7 498.1 4306.2 2414.8 (mL) Mass CO2 (g) 1.10 0.98 8.46 4.74 Sample10 10 10 20.0 Mass (g) Theoretical 0.0 8.6 4.2 12.5 Sample Mass (g)Biodegraded 0.60 0.48 4.29 2.84 Mass (g) Percent −1.4 87.4 18.0Biodegraded (%) * Adjusted −1.6 100.0 20.6 Percent Biodegraded (%)

Example 2

A bi-component fibre with polyethylene terephthalate (PET) as core(thermoplastic polymer A) and polypropylene (PP) as shell (sheath)(thermoplastic polymer B) is spun from a polyethylene terephthalate(PET) resin and a polypropylene (PP) resin having the followingproperties:

The melt extrusion is done by an extruder having one or more screws at atemperature of 270° C. for PET and by another extruder having one ormore screws at a temperature at a temperature of 250° C. for PP.

Additive A is added to the PET at the extruder feed-throat at a level of2 wt.-% masterbatch dosage. This masterbatch consists of a PET polyesteras carrier and the additive, which comprises an aliphatic polyester andCaCO3.

Additive B is added to the PP at the extruder feed-throat at a level of2 wt.-% masterbatch dosage. This masterbatch consists of PP as carrierand the additive, which comprises transition metal compounds andunsaturated carboxylic acids.

The fibre quench occurs by crossflow and air temperature of 20° C.;fibre drawdown speed is 1000 m/min. Spun fiber fineness is 5.4 dtex. Thefibre drawing is done by can be single or duo-stage drawing with drawratio up to 4 and the final dtex is 2.5 dtex. Heat setting is done at110-130° C. The fibre produced is cut into staple fibre having a lengthof 38 mm and a nonwoven is produced by thermo-bonding.

A nonwoven thus produced is kept as control in a sealed, evacuated bagand another nonwoven thus produced is tested over a one year period (365days) at 60° C. and 60% relative humidity.

The degradation is shown in FIG. 2 a-e versus the control. Thedegradation of the PP sheath becomes clearly visible. FIG. 2 eillustrates the degradation of the PET core as the shape of the fractionchanges clearly from the mushroom-shape, which is typical for PET, to ashape indicating that the material has become brittle. In this test thefibers have been axially stressed in a reproducible way (defined speed)by a mechanical testing machine.

The core of this bico fiber has the same material composition (polymerand additive) as the fiber described in Example 1, where degradation hasbeen proven according to ASTM D5511.

Example 3

A bi-component fibre with polyethylene terephthalate (PET) as core(thermoplastic polymer A) and co-polyethlyene terephthalate (coPET) asshell (sheath) (thermoplastic polymer B) is spun from a polyethyleneterephthalate (PET) resin and a co-polyethlyene terephthalate (coPET)resin having the following properties:

The melt extrusion is done by an extruder having one or more screws at atemperature of 290° C. for PET and by another extruder having one ormore screws at a temperature at a temperature of 280° C. for coPET.

Additive A is added to the PET at the extruder feed-throat at a level of2 wt.-% masterbatch dosage. This masterbatch consists of a PET polyesteras carrier and the additive, which comprises an aliphatic polyester andCaCO3.

Additive B is added to the coPET at the extruder feed-throat at a levelof 2% masterbatch dosage. This additive B is identical to additive A.

The fibre quench occurs by crossflow and air temperature of 35° C.;fibre drawdown speed is 1200 m/min, Spun fiber fineness is 5.4 dtex. Thefibre drawing is done by single or duo-stage drawing with draw ratio upto 4.5 and the final dtex is 2.5 dtex. Heat setting is done at 80° C.,The fibre produced is cut into staple fibre having a length of 38 mm anda nonwoven is produced by thermo-bonding.

The resulting fiber meets all requirements imposed. The core of thisbico fiber has the same material composition (polymer and additive) asthe fiber described in Example 1, where degradation has been provenaccording to ASTM D5511. The sheath differs in that the melting point ofthe copolyester is lower than the polyester of the core, which renderspossible to use the fiber for thermobonded nonwovens.

Various modifications and alterations to this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention. Illustrative embodiments and examples areprovided as examples only and are not intended to limit the broadestscope of the present invention.

1. A multi-component polymer fiber containing (i) at least one componentA and at least one component B, (ii) the component A comprising athermoplastic polymer A, (iii) the component B comprising athermoplastic polymer B, characterized in that (iv) the component Aadditionally has at least one additive A which increases the biologicaldegradability of the multi-component fiber and the component B does nothave an additive B which increases the biological degradability of themulti-component fiber, or (v) the component B additionally has at leastone additive B which increases the biological degradability of themulti-component fiber and the component A does not have an additive Awhich increases the biological degradability of the multi-componentfiber, or (vi) the component A additionally has at least one additive Aand the component B additionally has at least one additive B whichtogether increase the biological degradability of the multi-componentfiber, with the proviso that when (i) the thermoplastic polymer A andthe thermoplastic polymer B are identical, the additives A and B aredifferent, or (ii) when the additives A and B are identical,thermoplastic polymer A and thermoplastic polymer B are different. 2.The multi-component polymer fiber as claimed in claim 1, characterizedin that the thermoplastic polymer A and/or the thermoplastic polymer Bis/are selected from the group: (i)acrylonitrile-ethylene-propylene-(diene)-styrene copolymer,acrylonitrile-methacrylate copolymer, acrylonitrile-methylmethacrylatecopolymer, chlorinated acrylonitrile, polyethylene-styrene copolymer,acrylonitrile-butadiene-styrene copolymer,acrylonitrile-ethylene-propylene-styrene copolymer, celluloseacetobutyrate, cellulose acetopropionate, hydrated cellulose,carboxymethylcellulose, cellulose nitrate, cellulose propionate,cellulose triacetate, polyvinyl chloride, ethylene-acrylic acidcopolymer, ethylene-butylacrylate copolymer,ethylene-chlorotrifluoroethylene copolymer, ethylene-ethlyacrylatecopolymer, ethylene-methacrylate copolymer, ethylene-methacrylic acidcopolymer, ethylene-tetrafluoroethylene copolymer, ethylene-vinylalcohol copolymer, ethylene-butene copolymer, ethylcellulose,polystyrene, polyfluoroethylene-propylene,methylmethacrylate-acrylonitrile-butadiene styrene copolymer,methylmethacrylate-butadiene-styrene copolymer, methylcellulose,polyamide 11, polyamide 12, polyamide 46, polyamide 6, polyamide 6-3-T,polyamide 6-terephthalic acid copolymer, polyamide 66, polyamide 69,polyamide
 610. polyamide 612, polyamide 61, polyamide MXD 6, polyamidePDA-T, polyamide, polyarylether, polyaryletherketone, polyamideimide,polyarylamide, polyamino-bis-maleimide, polyarylate, polybutene-1,polybutylacrylate, polybenzimidazole, poly-bis-maleimide,polyoxadiazobenzimidazole, polybutylterephthalate, polycarbonate,polychlorotrifluoroethylene, polyethylene, polyestercarbonate,polyaryletherketone, polyetheretherketone, polyetherimide,polyetherketone, polyethylene oxide, polyarylether sulphone,polyethylene terephthalate, polyimide, polyisobutylene,polyisocyanurate, polyimide sulphone, polymethacrylimide,polymethacrylate, poly-4-methylpentene, polyacetal, polypropylene,polyphenyl oxide, polypropylene oxide, polyphenylene sulphide,polyphenylene sulphone, polystyrene, polysulphone,polytetrafluoroethylene, polyurethane, polyvinyl acetate, polyvinylalcohol, polyvinylbutyral, polyvinyl chloride, polyvinylidene chloride,polyvinylidene fluoride, polyvinyl fluoride, polyvinyl methyl ether,polyvinylpyrrolidone, styrene-butadiene copolymer, styrene-isoprenecopolymer, styrene-maleic acid anhydride copolymer, styrene-maleic acidanhydride-butadiene copolymer, styrene methyl methacrylate copolymer,styrene-methyl styrene copolymer, styrene-acrylonitrile copolymer, vinylchloride-ethylene copolymer, vinyl chloride-methacrylate copolymer,vinyl chloride-maleic acid anhydride copolymer, vinyl chloride-maleimidecopolymer, vinyl chloride-methylmethacrylate copolymer, vinylchloride-octyl acrylate copolymer, vinyl chloride-vinyl acetatecopolymer, vinyl chloride-vinylidene chloride copolymer, vinylchloride-vinylidene chloride-acrylonitrile copolymer and/or (ii)synthetic biopolymer.
 3. The multi-component polymer fiber as claimed inclaim 2, characterized in that the synthetic biopolymers may be one ormore aliphatic, araliphatic polyesters or copolyesters which areproduced from polyols, and aliphatic and/or aromatic dicarboxylic acidsor their derivatives (anhydrides, esters) by polycondensation, whereinthe polyols may be substituted or unsubstituted, and the polyols may belinear or branched polyols.
 4. The multi-component polymer fiber asclaimed in claim 3, characterized in that (i) the polyols contain 2 to 8carbon atoms, (ii) the aliphatic dicarboxylic acids comprise substitutedor unsubstituted, linear or branched, non-aromatic dicarboxylic acidsselected from the group formed by aliphatic dicarboxylic acidscontaining 2 to 12 carbon atoms and cycloaliphatic dicarboxylic acidscontaining 5 to 10 carbon atoms, wherein the cycloaliphatic dicarboxylicacids may also contain heteroatoms in the ring, (iii) the aromaticdicarboxylic acids comprise substituted or unsubstituted, aromaticdicarboxylic acids selected from the group formed by aromaticdicarboxylic acids containing 6 to 12 carbon atoms, wherein thesecarboxylic acids may also comprise heteroatoms in the aromatic ringand/or in the substituents, (iv) the substituted aromatic dicarboxylicacids contain 1 to 4 substituents selected from halogens, C6-C10 aryland C1-C4 alkoxy.
 5. The multi-component polymer fiber as claimed inclaim 1, characterized in that the synthetic biopolymer is selected fromthe group formed by aliphatic polyesters with repeat units of at least 4carbon atoms, for example polyhydroxyalkanoates such aspolyhydroxyvalerate and polyhydroxybutyrate-hydroxyvalerate copolymer,polycaprolactone, furan dicarboxylic acid, and succinate-based aliphaticpolymers (for example polybutylene succinate, polybutylene succinateadipate and polyethylene succinate). Special examples may be selectedfrom polyethylene oxalate, polyethylene malonate, polyethylenesuccinate, polypropylene oxalate, polypropylene malonate, polypropylenesuccinate, polybutylene oxalate, polybutylene malonate, polybutylenesuccinate and blends and copolymers of these compounds.
 6. Themulti-component polymer fiber as claimed in claim 1, characterized inthat the synthetic biopolymer is an aliphatic polyester comprisingrepeat units of lactic acid (PLA), hydroxy fatty acid (PHF) (also knownas polyhydroxyalkanoate PHA), in particular hydroxybutanoic acid (PHB)and succinate-based aliphatic polymers, for example polybutylenesuccinate, polybutylene succinate adipate and polyethylene succinate).7. The multi-component polymer fiber as claimed claim 1, characterizedin that the thermoplastic polymer A and/or B has a glass transitiontemperature in the range −125° C. to 200° C., in particular in the range−125° C. to 100° C., or characterized in that the thermoplastic polymerA and/or B has a melting temperature in the range 120° C. to 285° C., inparticular in the range 150° C. to 270° C., particularly preferably inthe range 175° C. to 270° C.
 8. The multi-component polymer fiber asclaimed in claim 1, characterized in that the thermoplastic polymer Aand/or B is/are selected from the group formed by polylactic acids (PLA)as well as their copolymers, polyhydroxy fatty acid esters (PHF) as wellas their copolymers, as well as blends of said polymers, orcharacterized in that at least the thermoplastic polymer A and/or thethermoplastic polymer B is/are selected from the group formed by meltspinnable synthetic biopolymers, wherein polycondensates andpolymerisates from bio-based starting materials are particularlypreferred.
 9. The multi-component polymer fiber as claimed in claim 1,characterized in that the multi-component polymer fiber is abi-component fiber in which the component A forms the core and thecomponent B forms the shell and the melting point of the thermoplasticpolymer in component A is at least 5° C., preferably at least 10° C.,higher than the melting point of the thermoplastic polymer in componentB.
 10. The multi-component polymer fiber as claimed in claim 1,characterized in that the fiber has (i) at least one additive A in thecomponent A or (ii) at least one additive B in the component B or (iii)at least one additive A in the component A and at least one additive Bin the component B, with the proviso that the additive A and theadditive B are different or insofar as at least one additive A ispresent in the component A and at least one additive B is present in thecomponent B, the additive A and the additive B may also be identical,when the thermoplastic polymer A and thermoplastic polymer B aredifferent.
 11. The multi-component polymer fiber as claimed in claim 1,characterized in that the additives A and B are selected from the group:(i) basic alkali and/or alkaline earth compounds (pH>7 dissolved inwater), in particular carbonates, hydrogen carbonates, sulphates,particularly preferably CaCO3, and alkaline additives, particularlypreferably CaO, (ii) aliphatic polyesters, (iii) fatty acid ester,preferably C1-C40-alkyl stearate, more preferred C2-C20-alkyl stearate,most preferred ethyl stearate (iv) sugars, in particularmonosaccharides, disaccharides and oligosaccharides, (v) catalysts fortransesterification, in particular under basic conditions, (vi) metalcompounds, in particular transition metal compounds, as well as theirsalts, (vii) unsaturated carboxylic acids or theiranhydrides/esters/amides, (viii) synthetic rubber, natural rubber, (ix)carbohydrates, in particular starch and/or cellulose, as well asmixtures of the aforementioned substances.
 12. The multi-componentpolymer fiber as claimed claim 1, characterized in that the additive Ahas a proportion of the component A which is preferably between 0.005%by weight and 20% by weight, particularly preferably between 0.01% byweight and 5% by weight, with respect to the total weight of thecomponent A and the additive B has a proportion of the component B whichis preferably between 0.005% by weight and 20% by weight, particularlypreferably between 0.01% by weight and 5% by weight, with respect to thetotal weight of the component B.
 13. The multi-component polymer fiberas claimed in claim 1, characterized in that the fiber is a continuousfiber, preferably a staple fiber, or is a continuous filament, and ispreferably a bi-component fiber.
 14. The multi-component polymer fiberas claimed in claim 1, characterized in that the fiber has an increasedbiological degradability compared with a multi-component fiber withoutthe additives A and/or B, and the biological degradability is determinedin accordance with at least one method selected from the group: (i) ASTMD5338-15 (2021) Standard Test Method for Determining AerobicBiodegradation of Plastic Materials Under Controlled CompostingConditions, Incorporating Thermophilic Temperatures(DOI:10.1520/D5338-15R21) ASTM International, West Conshohocken, P A,2015, www.astm.org), (ii) ASTM D6400-12 (Standard Specification forLabeling of Plastics Designed to be Aerobically Composted in Municipalor Industrial Facilities) (DOI: 10.1520/D6400-12), (iii) ASTM D5511(ASTM D5511-11 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-SolidsAnaerobic-digestion Conditions (DOI: 10.1520/D5511-11) and ASTM D5511-18Standard Test Method for Determining Anaerobic Biodegradation of PlasticMaterials Under High-Solids Anaerobic-digestion Conditions; (DOI:10.1520/D5511-18)), (iv) ASTM D6691 (ASTM D6691-09 Standard Test Methodfor Determining Aerobic Biodegradation of Plastic Materials in theMarine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum) (DOI: 10.1520/D6691-09) and ASTM D6691-17, Standard TestMethod for Determining Aerobic Biodegradation of Plastic Materials inthe Marine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum (DOI: 10.1520/D6691-17)), (v) ASTM D5210-92 (AnaerobicDegradation in the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92),(vi) PAS 9017:2020 (Plastics—Biodegradation of polyolefins in anopen-air terrestrial environment—Specification), ISBN 978 0 539 17478 6;2021-10-31, (vii) ASTM D5988 (ASTM D5988-12 Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in Soil) (DOI:10.1520/D5988-12), ASTM D5988-18 Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials in Soil (DOI:10.1520/D5988-18), ASTM D5988-03 Standard Test Method for DeterminingAerobic Biodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), (viii) EN13432:2000-12 Packaging—Requirements for packaging recoverable throughcomposting and biodegradation—Test scheme and evaluation criteria forthe final acceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS 83.080.01) Determination of the ultimateaerobic biodegradability of plastic materials under controlledcomposting conditions (Method by analysis of evolved carbon dioxide),(x) EN 14995:2007-03— Plastics—Evaluation of compostability (DOI:10.31030/9730527) or (xii) ISO 17088:2021-04 (Specifications forcompostable plastics) (ICS 83.080.01).
 15. A bi-component fiber with acore/shell structure, wherein (i) the component A forms the core and thecomponent B forms the shell of the fiber, (ii) the component A in thecore comprises thermoplastic polymer A, (iii) the component B comprisesa thermoplastic polymer B, (iv) the melting point of the thermoplasticpolymer in the component A in the core is at least 5° C. higher than themelting point of the thermoplastic polymer in the component B in theshell, and preferably the melting point is at least 10° C. higher,characterized in that (v) the component A has a higher biologicaldegradability than the component B; preferably, the component A has atleast one additive A, or (vi) the component B has a higher biologicaldegradability than the component A; preferably, the component B has atleast one additive B.
 16. The bi-component fiber as claimed in claim 15,characterized in that the biological degradability is determined inaccordance with at least one method selected from the group: (i) ASTMD5338-15 (2021) Standard Test Method for Determining AerobicBiodegradation of Plastic Materials Under Controlled CompostingConditions, Incorporating Thermophilic Temperatures(DOI:10.1520/D5338-15R21) ASTM International, West Conshohocken, P A,2015, www.astm.org), (ii) ASTM D6400-12 (Standard Specification forLabeling of Plastics Designed to be Aerobically Composted in Municipalor Industrial Facilities) (DOI: 10.1520/D6400-12), (iii) ASTM D5511(ASTM D5511-11 Standard Test Method for Determining AnaerobicBiodegradation of Plastic Materials Under High-SolidsAnaerobic-digestion Conditions (DOI: 10.1520/D5511-11) and ASTM D5511-18Standard Test Method for Determining Anaerobic Biodegradation of PlasticMaterials Under High-Solids Anaerobic-digestion Conditions; (DOI:10.1520/D5511-18)), (iv) ASTM D6691 (ASTM D6691-09 Standard Test Methodfor Determining Aerobic Biodegradation of Plastic Materials in theMarine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum) (DOI: 10.1520/D6691-09) and ASTM D6691-17, Standard TestMethod for Determining Aerobic Biodegradation of Plastic Materials inthe Marine Environment by a Defined Microbial Consortium or Natural SeaWater Inoculum (DOI: 10.1520/D6691-17)), (v) ASTM D5210-92 (AnaerobicDegradation in the Presence of Sewage Sludge) (DOI: 10.1520/D5210-92),(vi) PAS 9017:2020 (Plastics—Biodegradation of polyolefins in anopen-air terrestrial environment—Specification), ISBN 978 0 539 17478 6;2021-10-31, (vii) ASTM D5988 (ASTM D5988-12 Standard Test Method forDetermining Aerobic Biodegradation of Plastic Materials in Soil) (DOI:10.1520/D5988-12), ASTM D5988-18 Standard Test Method for DeterminingAerobic Biodegradation of Plastic Materials in Soil (DOI:10.1520/D5988-18), ASTM D5988-03 Standard Test Method for DeterminingAerobic Biodegradation in Soil of Plastic Materials or Residual PlasticMaterials After Composting (DOI: 10.1520/D5988-03)), (viii) EN13432:2000-12 Packaging—Requirements for packaging recoverable throughcomposting and biodegradation—Test scheme and evaluation criteria forthe final acceptance of packaging; German version EN 13432:2000 (DOI:10.31030/9010637), (ix) ISO 14855-1:2013-04 (DOI: 10.31030/1939267) andISO 14855-2:2018-07 (ICS 83.080.01) Determination of the ultimateaerobic biodegradability of plastic materials under controlledcomposting conditions (Method by analysis of evolved carbon dioxide),(x) EN 14995:2007-03— Plastics—Evaluation of compostability (DOI:10.31030/9730527), or (xi) ISO 17088:2021-04 (Specifications forcompostable plastics) (ICS 83.080.01).
 17. The bi-component fiber asclaimed in claim 15, characterized in that the additive A and/oradditive B is selected from the group formed by (i) basic alkali and/oralkaline earth compounds (pH>7 dissolved in water), in particularcarbonates, hydrogen carbonates, sulphates, particularly preferablyCaCO3, and alkaline additives, particularly preferably CaO, (ii)aliphatic polyesters, (iii) fatty acid ester, preferably C1-C40-alkylstearate, more preferred C2-C20-alkyl stearate, most preferred ethylstearate, (iv) sugars, in particular mono-saccharides, di-saccharidesand oligo-saccharides, (v) catalysts for transesterifications, inparticular under basic conditions, (vi) carbohydrates, in particularstarch and/or cellulose, as well as mixtures thereof.
 18. Thebi-component fiber as claimed in claim 15, characterized in that thethermoplastic polymer A and/or the thermoplastic polymer B comprises atleast one polyester, with the proviso that the polyester is anaraliphatic polyester or copolyester in the case in which the additive Aand/or B is an aliphatic polyester, or characterized in that theadditive A and/or additive B is selected from the group formed by A)basic alkali and/or alkaline earth compounds (pH>7 dissolved in water),in particular carbonates, hydrogen carbonates, sulphates, particularlypreferably CaCO3, and alkaline additives, particularly preferably CaO incombination with catalysts for transesterifications, in particular underbasic conditions; B) sugars, in particular mono-saccharides,di-saccharides and oligo-saccharides, in combination with carbohydrates,in particular starch and/or cellulose, as well as mixtures thereof; C)aliphatic polyesters in combination with sugars, in particularmono-saccharides, di-saccharides and oligo-saccharides, orcarbohydrates, in particular starch and/or cellulose, D) fatty acidester, preferably C1-C40-alkyl stearate, more preferred C2-C20-alkylstearate, most preferred ethyl stearate, as well as mixtures thereof.19. The multi-component polymer fibers as claimed in claim 1, whereinsaid multi-component polymer fibers are incorporated into a textilefabric and characterized in that the textile fabric is a nonwoven, inparticular a wet laid nonwoven or a dry laid nonwoven, preferably basedon staple fibers, wherein the nonwoven is preferably consolidated bythermobonding, or characterized in that the textile fabric, inparticular the nonwoven, has a basis weight between 10 and 500 g/m2,preferably 25 to 450 g/m2, in particular 30 to 300 g/m2.
 20. Use of themulti-component polymer fiber as claimed in claim 1.